⚡ Quick Start — If You Read Nothing Else

The 8 most important things to know right now.

hATTR-PN is a treatable genetic disease — early treatment changes everything. Hereditary ATTR amyloidosis with polyneuropathy is caused by mutations in the TTR gene. The misfolded protein deposits in nerves and organs. Since 2018, multiple FDA-approved therapies can slow or halt disease progression, and some patients experience improvement.
Genetic testing confirms the diagnosis. A simple blood test for TTR gene mutations is the cornerstone of diagnosis. Over 150 mutations are known, with Val30Met being the most common worldwide.
There are two main classes of disease-modifying therapy: gene silencers and stabilizers. Gene silencers (patisiran, vutrisiran, inotersen, eplontersen) reduce production of the abnormal TTR protein and are FDA-approved for hATTR polyneuropathy. TTR stabilizers prevent the protein from misfolding; tafamidis is FDA-approved for ATTR cardiomyopathy (used off-label for polyneuropathy in the US, though it is approved for early polyneuropathy in Europe), and diflunisal is used off-label and is not FDA-approved for ATTR.
Vutrisiran and eplontersen are the newest therapies. Vutrisiran (Amvuttra) is an RNAi therapy given by subcutaneous injection every 3 months. Eplontersen (Wainua) is an antisense oligonucleotide given subcutaneously once monthly. Both offer significant convenience over older treatments.
hATTR often affects both nerves and heart. Many patients develop both polyneuropathy and cardiomyopathy. Cardiac screening is essential even if your primary symptoms are neurological.
Family screening is critical. hATTR-PN is autosomal dominant — each child of an affected parent has a 50% chance of inheriting the mutation. Genetic counseling and testing of at-risk family members can enable early treatment before symptoms appear.
Get to an amyloidosis center. hATTR-PN is rare and frequently misdiagnosed as more common neuropathies. Centers with amyloidosis expertise diagnose faster and provide coordinated multidisciplinary care.
Liver transplant is no longer first-line treatment. Before gene-silencing therapies were available, liver transplant was the only disease-modifying option. It is now reserved for selected cases, as drug therapies are more effective and less risky.

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Understanding Hereditary ATTR Amyloidosis with Polyneuropathy

Hereditary transthyretin amyloidosis with polyneuropathy (hATTR-PN) is a rare, progressive, and potentially life-threatening genetic disease. It is caused by mutations in the TTR (transthyretin) gene. Transthyretin is a protein made primarily by the liver that normally carries thyroid hormone and vitamin A (retinol) in the blood.

When the TTR gene is mutated, the protein becomes unstable and misfolds, forming insoluble fibers called amyloid that deposit in tissues throughout the body. In hATTR-PN, amyloid deposits preferentially damage peripheral nerves, causing progressive sensory, motor, and autonomic neuropathy. Many patients also develop amyloid deposits in the heart (cardiomyopathy), kidneys, eyes, and gastrointestinal tract.

Without treatment, hATTR-PN leads to progressive disability and is fatal, typically within 7 to 12 years of symptom onset. With modern disease-modifying therapies started early, disease progression can be slowed, halted, or in some cases partially reversed.

Approximately 50,000 people worldwide are estimated to have hATTR amyloidosis (polyneuropathy and/or cardiomyopathy)
The disease is endemic in certain regions: northern Portugal (Povoa de Varzim), northern Sweden (Skellefteå), Japan, and parts of Brazil
In endemic areas, prevalence can reach 1 in 1,000 people
In non-endemic areas, the disease is often sporadic and frequently misdiagnosed, with an average diagnostic delay of 4 to 5 years
Symptom onset is typically between ages 25 and 65, depending on the specific TTR mutation and geographic origin

There are two forms of ATTR amyloidosis:

Hereditary (hATTR): Caused by an inherited TTR gene mutation. Affects nerves and/or heart. Onset typically before age 70. Autosomal dominant inheritance (50% chance of passing to each child).
Wild-type ATTR (wtATTR): Not inherited. Normal (wild-type) TTR protein misfolds with aging. Primarily causes cardiomyopathy. Almost exclusively affects men over age 65. Previously called “senile cardiac amyloidosis.” Much more common than hATTR (estimated 200,000+ affected in the US).

This guide focuses on hereditary ATTR with polyneuropathy. Some treatments (especially tafamidis for cardiomyopathy) are used in both hereditary and wild-type forms.

The most important concept in this guide: hATTR-PN is now a treatable disease. The revolution in gene-silencing therapies since 2018 means that patients diagnosed early can expect dramatically better outcomes than in previous decades. The key is early diagnosis and early treatment — before irreversible nerve damage occurs. If you have unexplained neuropathy with autonomic symptoms and a family history, insist on TTR genetic testing.

Key Breakthroughs in hATTR-PN

The treatment landscape for hATTR-PN has been transformed since 2018, with four FDA-approved disease-modifying therapies and several more in development.

FDA-APPROVED Patisiran was the first-ever RNA interference (RNAi) therapy approved for any disease. The APOLLO trial demonstrated that patisiran halted and in many patients reversed neuropathy progression compared to placebo. Given as an IV infusion every 3 weeks, patisiran reduces TTR protein production by approximately 80%. It marked a paradigm shift from treating symptoms to addressing the root cause of the disease.

FDA-APPROVED Vutrisiran is a next-generation RNAi therapy that builds on patisiran but uses GalNAc conjugation technology for liver-targeted delivery. This allows subcutaneous injection every 3 months instead of IV infusion every 3 weeks. The HELIOS-A trial showed non-inferiority to patisiran and statistically significant improvement over an external placebo. It has become the preferred RNAi option for many patients due to convenience. In March 2025, vutrisiran also became FDA-approved for ATTR cardiomyopathy (based on the HELIOS-B trial), making it the first therapy approved for both the polyneuropathy and the cardiomyopathy of ATTR — useful for the many patients with a mixed phenotype.

FDA-APPROVED Inotersen is an antisense oligonucleotide (ASO) that degrades TTR messenger RNA in the liver. The NEURO-TTR trial showed significant improvement in neuropathy and quality of life compared to placebo. Given as a weekly subcutaneous injection by the patient at home. It is dispensed through a REMS program and requires regular platelet and kidney monitoring due to risks of serious thrombocytopenia and glomerulonephritis. Largely succeeded by eplontersen.

FDA-APPROVED Eplontersen is a ligand-conjugated antisense oligonucleotide (LICA) with GalNAc targeting, enabling once-monthly subcutaneous self-injection. The NEURO-TTRansform trial showed superiority over inotersen with a substantially improved safety profile — no thrombocytopenia signal and no requirement for regular platelet monitoring. It reduces serum TTR by approximately 80–85%. Eplontersen has rapidly become a leading treatment option.

FDA-APPROVED (Cardiomyopathy) Tafamidis stabilizes the TTR tetramer, preventing it from dissociating and misfolding into amyloid. It was approved in the EU in 2011 for early-stage hATTR-PN (stage 1) and in the US in 2019 for ATTR cardiomyopathy (both hereditary and wild-type). The ATTR-ACT trial showed reduced mortality and cardiovascular hospitalizations. While FDA-approved for cardiomyopathy rather than polyneuropathy specifically, it is commonly used in hATTR patients with mixed (neuropathy + cardiomyopathy) phenotypes.

OFF-LABEL Diflunisal is an inexpensive NSAID (non-steroidal anti-inflammatory drug) that also stabilizes the TTR tetramer. A randomized trial published in JAMA in 2013 showed it slowed neuropathy progression compared to placebo over 2 years. It is used off-label in some countries where other therapies are unavailable or as an adjunct. Requires monitoring for GI bleeding, renal function, and cardiac effects (fluid retention). Not FDA-approved for hATTR but included in treatment guidelines as an option.

Diagnosis: The Tests You Need

hATTR-PN is notoriously difficult to diagnose because its symptoms mimic many more common conditions, including diabetic neuropathy, chronic inflammatory demyelinating polyneuropathy (CIDP), and idiopathic small fiber neuropathy. The average diagnostic delay is 4 to 5 years. A high index of suspicion is the most important diagnostic tool.

Progressive sensorimotor polyneuropathy with autonomic features (especially orthostatic hypotension, GI dysmotility, erectile dysfunction, urinary problems)
Family history of neuropathy, cardiomyopathy, or “familial amyloidosis”
Ancestry from endemic regions: Portugal, Sweden, Japan, Brazil, or West Africa (Val122Ile is common in African Americans)
Bilateral carpal tunnel syndrome (especially requiring surgical release before age 50)
Unexplained heart failure with preserved ejection fraction and increased wall thickness, especially with neuropathy
Neuropathy that does not respond to standard treatments for CIDP or diabetic neuropathy
Vitreous opacities or abnormal eye findings with neuropathy

Genetic testing for TTR mutations is the definitive diagnostic test. It requires only a blood sample or saliva sample and can be ordered by any physician. Results typically return within 2 to 4 weeks.

What it detects: Any of the 150+ known pathogenic mutations in the TTR gene
Who should be tested: Anyone with suspected hATTR-PN, family members of known carriers, and patients with unexplained neuropathy plus red flag features
Cost: Often covered by insurance when clinically indicated. Free or low-cost testing programs exist (e.g., manufacturer-sponsored programs through Alnylam and Ionis)
Interpretation: A positive result confirms the diagnosis when combined with clinical symptoms. A positive result in an asymptomatic person identifies a carrier who should be monitored

While genetic testing confirms the TTR mutation, tissue biopsy can confirm amyloid deposition. Common biopsy sites include:

Abdominal fat pad aspirate: Least invasive. Sensitivity ~70–80% in hATTR-PN
Salivary gland biopsy: Higher sensitivity (~85–90%) for hATTR-PN
Sural nerve biopsy: Direct confirmation in nerve tissue. Reserved for cases where other biopsies are negative but suspicion remains high
Endomyocardial biopsy: Gold standard for cardiac involvement but invasive; usually reserved when non-invasive cardiac imaging is inconclusive

Amyloid deposits are identified by Congo red staining (apple-green birefringence under polarized light) and typed by mass spectrometry or immunohistochemistry to confirm ATTR type.

Nerve conduction studies (NCS) and electromyography (EMG): Assess large fiber neuropathy (sensory and motor nerve function). Key for staging and monitoring treatment response.
Quantitative sensory testing (QST): Measures thermal and vibration thresholds. Detects small fiber dysfunction.
Skin biopsy for intraepidermal nerve fiber density (IENFD): Quantifies small nerve fiber loss. Abnormal in early hATTR-PN when NCS may still be normal.
Autonomic testing: Tilt table test, QSART (sweat testing), heart rate variability. Assesses autonomic neuropathy severity.
NIS (Neuropathy Impairment Score): Standardized neurological examination score. The modified NIS+7 is used in clinical trials as a primary endpoint.

Because hATTR frequently involves the heart, every patient with hATTR-PN should have cardiac screening:

Echocardiogram: Measures wall thickness, diastolic function, and strain patterns. The “sparkling” appearance and increased wall thickness are suggestive.
Cardiac MRI with gadolinium: Late gadolinium enhancement (LGE) and elevated native T1 values detect amyloid infiltration.
Technetium pyrophosphate (PYP) scan: Nuclear imaging that detects ATTR amyloid in the heart. Highly specific for ATTR cardiac amyloidosis (grade 2–3 uptake). Does not distinguish hereditary from wild-type.
NT-proBNP and troponin: Blood biomarkers of cardiac stress and damage. Elevated in cardiac amyloidosis.
ECG: May show low voltage (despite thick walls), conduction abnormalities, or pseudo-infarction pattern.

Have you tested me for TTR gene mutations?
What specific TTR mutation do I have, and what does it mean for my prognosis?
Has amyloid been confirmed in tissue (biopsy)?
Do I have cardiac involvement? What did the echocardiogram and cardiac imaging show?
What is my current disease stage (FAP stage)?
Should my family members be tested for this mutation?
Have you ruled out other causes of my neuropathy?
Should I see a genetic counselor?

Genetics & TTR Mutations

hATTR-PN is an autosomal dominant genetic disease, meaning you only need one copy of the mutated gene (from one parent) to be at risk. Over 150 different mutations in the TTR gene have been identified. The specific mutation influences age of onset, organ involvement, disease severity, and geographic distribution.

Mutation	Also Called	Endemic Region	Primary Phenotype
Val30Met (V30M)	p.Val50Met	Portugal, Sweden, Japan, Brazil	Predominantly polyneuropathy; early onset (20s–40s) in endemic areas, later onset (50s–70s) in non-endemic areas
Val122Ile (V122I)	p.Val142Ile	West African descent; ~3.5% of African Americans carry this variant	Predominantly cardiomyopathy; neuropathy can be present. Late onset (60s–80s)
Thr60Ala (T60A)	p.Thr80Ala	Ireland, UK (northwest)	Mixed neuropathy and cardiomyopathy
Ser77Tyr (S77Y)	p.Ser97Tyr	France, Italy	Mixed; cardiac involvement common
Ile68Leu (I68L)	p.Ile88Leu	Italy	Mixed neuropathy and cardiomyopathy

Penetrance refers to the percentage of mutation carriers who actually develop the disease. hATTR-PN has incomplete penetrance, meaning not everyone who carries the mutation will develop symptoms:

In endemic areas (Portugal), penetrance for Val30Met can exceed 80% by age 50
In non-endemic areas (Sweden, other), penetrance may be lower (11–36%) and onset later
The same mutation can cause different symptoms in different family members
Genetic modifiers, epigenetics, and environmental factors likely influence penetrance

This means a positive genetic test in an asymptomatic person does not guarantee they will develop the disease, but it does mean they should be monitored regularly.

Every patient diagnosed with hATTR-PN should be offered genetic counseling
First-degree relatives (children, siblings, parents) should be offered TTR genetic testing
Prenatal and preimplantation genetic testing is available for known familial mutations
Asymptomatic carriers should be monitored annually with neurological exam, cardiac evaluation (echo, NT-proBNP), and nerve conduction studies
The decision to undergo genetic testing is personal. Some family members may choose not to be tested, and that choice should be respected

Key question for your neurologist: “What specific TTR mutation do I have, and does it typically cause neuropathy, cardiomyopathy, or both? What does it mean for my family members?”

Disease Staging — FAP Stages

hATTR-PN is staged using the FAP (Familial Amyloid Polyneuropathy) staging system developed by Coutinho. Staging guides treatment decisions and helps predict prognosis.

FAP Stage	Description	Mobility	Treatment Implications
Stage 1	Mild sensory neuropathy, mostly in feet and legs. Autonomic symptoms may be present. Can walk without assistance.	Unimpaired ambulation	Best outcomes with treatment. All approved therapies are effective. Start disease-modifying therapy immediately.
Stage 2	Moderate neuropathy with motor involvement. Difficulty walking without assistance. Upper limb involvement.	Requires assistance for walking	Treatment can stabilize but less likely to reverse deficits. Gene silencers (patisiran, vutrisiran, eplontersen) are preferred.
Stage 3	Severe neuropathy. Wheelchair-bound or bedridden. Significant autonomic dysfunction. Cardiac and renal involvement common.	Wheelchair-bound or bedridden	Treatment may slow further decline but cannot reverse established damage. Supportive care is critical. Quality of life focus.

Important: FAP staging is not destiny. Early treatment at stage 1 produces the best outcomes, but treatment at stage 2 can still stabilize disease and improve quality of life. Even at stage 3, disease-modifying therapy may prevent further organ damage. No stage is “too late” to consider treatment, though expectations should be adjusted.

Gene-Silencing Therapies

Gene-silencing therapies work by reducing the liver’s production of TTR protein. Less TTR in the blood means less misfolded protein available to form amyloid deposits. There are two mechanisms: RNA interference (RNAi) and antisense oligonucleotides (ASO). Both reduce serum TTR by approximately 80% or more.

FDA-APPROVED 2018 For hATTR polyneuropathy in adults

How it works: Small interfering RNA (siRNA) encapsulated in lipid nanoparticles. After IV infusion, the nanoparticles are taken up by liver cells, where the siRNA silences TTR mRNA, reducing TTR protein production by ~80%.
Dosing: 0.3 mg/kg IV infusion every 3 weeks. Requires premedication with corticosteroid, acetaminophen, H1 and H2 blockers. Infusion takes approximately 80 minutes.
Key trial (APOLLO, NCT01960348): 225 patients, 18-month randomized, placebo-controlled. Patisiran improved neuropathy (mNIS+7 score) by 34 points vs. placebo. 56% of patisiran patients showed neurological improvement from baseline vs. 4% on placebo.
Side effects: Infusion-related reactions (managed with premedication), vitamin A deficiency (supplement recommended). Generally well tolerated.

FDA-APPROVED 2022 For hATTR polyneuropathy in adults

How it works: Enhanced stabilization chemistry siRNA conjugated to GalNAc (N-acetylgalactosamine), which targets liver cells directly. No lipid nanoparticle needed, enabling subcutaneous administration.
Dosing: 25 mg subcutaneous injection every 3 months. Administered by healthcare provider or self-injection after training. No premedication required.
Key trial (HELIOS-A, NCT03759379): 164 patients, 18-month study. Vutrisiran showed non-inferiority to patisiran (external reference) and significant improvement over external placebo in mNIS+7 and Norfolk QoL-DN scores. Serum TTR reduction ~80%.
Advantages over patisiran: Subcutaneous injection every 3 months vs. IV infusion every 3 weeks. No premedication. Can be done at home after training.
Side effects: Injection site reactions, arthralgia, vitamin A deficiency. Requires vitamin A supplementation.

FDA-APPROVED 2018 For hATTR polyneuropathy in adults

How it works: Antisense oligonucleotide that binds to TTR mRNA in the liver and targets it for degradation by RNase H.
Dosing: 284 mg subcutaneous injection once weekly. Self-administered at home.
Key trial (NEURO-TTR, NCT01737398): 172 patients, 15-month randomized, placebo-controlled. Inotersen significantly improved mNIS+7 and Norfolk QoL-DN scores vs. placebo.
Important safety concerns: Thrombocytopenia (low platelets) in ~3% of patients, including fatal cases. Glomerulonephritis (kidney inflammation). Requires regular platelet count monitoring (every 2 weeks) and kidney function monitoring. Carries an FDA boxed warning.
Note: Eplontersen (Wainua) is the next-generation replacement for inotersen with a much improved safety profile.

FDA-APPROVED 2023 For hATTR polyneuropathy in adults

How it works: Ligand-conjugated antisense oligonucleotide (LICA) with GalNAc targeting for enhanced liver uptake. Same antisense mechanism as inotersen but with vastly improved delivery and safety.
Dosing: 45 mg subcutaneous injection once monthly. Self-administered at home using an autoinjector.
Key trial (NEURO-TTRansform, NCT04136184): 168 patients; an open-label study in which efficacy was compared against an external placebo group from the earlier NEURO-TTR trial (with a small inotersen reference arm), with the final analysis at week 66. Eplontersen produced significant improvement versus placebo in neuropathy (mNIS+7) and quality of life, with ~80–85% serum TTR reduction.
Safety advantage over inotersen: No thrombocytopenia signal. No glomerulonephritis signal. No requirement for routine platelet monitoring. No boxed warning.
Side effects: Injection site reactions, falls, nausea. Generally well tolerated.

How to choose between gene silencers: All four approved gene silencers reduce TTR effectively. The choice often comes down to route/frequency of administration (IV every 3 weeks vs. SC monthly vs. SC quarterly), safety monitoring requirements (inotersen requires platelet checks), insurance coverage, and personal preference. Discuss with your amyloidosis specialist.

TTR Stabilizers

TTR stabilizers work differently from gene silencers. Instead of reducing TTR production, they bind to the TTR protein and prevent it from falling apart (dissociating) and misfolding into amyloid. They are most commonly used for cardiac involvement.

FDA-APPROVED For ATTR cardiomyopathy (both hereditary and wild-type)

How it works: Binds to thyroxine-binding sites on the TTR tetramer, stabilizing the protein and preventing dissociation and amyloid formation.
Dosing: Tafamidis meglumine 80 mg (Vyndaqel) PO daily, or tafamidis free acid 61 mg (Vyndamax) PO daily.
Key trial (ATTR-ACT, NCT01994889): 441 patients with ATTR cardiomyopathy. Tafamidis reduced all-cause mortality by 30% and cardiovascular hospitalizations by 32% over 30 months vs. placebo.
For polyneuropathy: Tafamidis was approved in the EU (2011) for stage 1 hATTR-PN based on the Fx-005 trial. It slowed neuropathy progression in early-stage disease. In the US, the polyneuropathy indication is off-label, but it is commonly used in patients with mixed neuropathy and cardiomyopathy.
Limitations: Less effective in advanced neuropathy (stage 2–3). Does not reduce TTR levels, only stabilizes the protein. Gene silencers are generally preferred for polyneuropathy.

OFF-LABEL

How it works: An NSAID that also binds to and stabilizes TTR tetramer. Not FDA-approved for hATTR but supported by a randomized trial.
Dosing: 250 mg PO twice daily.
Evidence: Berk et al., JAMA 2013 (NCT00294671): 130 patients, 2 years. Diflunisal reduced neuropathy progression compared to placebo (NIS+7 worsened by 8.3 points vs. 18.3 points).
Advantages: Inexpensive. Oral administration. Available worldwide.
Risks: GI bleeding, renal impairment, fluid retention (caution in cardiac patients). Requires proton pump inhibitor co-prescription and regular renal monitoring. Contraindicated in severe renal or cardiac disease.

Which disease-modifying therapy do you recommend for me, and why?
Should I receive a gene silencer, a stabilizer, or both?
How will we monitor whether treatment is working?
What are the side effects I should watch for?
Do I have cardiac involvement that needs additional treatment?
How often will I need follow-up visits and testing?
Is there a clinical trial I should consider?
What happens if my disease progresses despite treatment?
Will I need vitamin A supplementation?
Are there patient assistance programs to help with the cost?

Symptom Management

Disease-modifying therapies address the root cause, but symptom management is equally important for quality of life. hATTR-PN causes a wide range of symptoms that require multidisciplinary care.

First-line: Gabapentin (300–3,600 mg/day) or pregabalin (150–600 mg/day)
Second-line: Duloxetine (60–120 mg/day), amitriptyline (10–75 mg at bedtime, use with caution in cardiac patients due to QT effects)
Topical: Lidocaine patches (5%) or capsaicin cream/patches for localized pain
Avoid: Opioids are generally discouraged for chronic neuropathic pain due to limited efficacy and risk of dependence and constipation (worsens GI autonomic dysfunction)

Orthostatic hypotension: Midodrine (2.5–10 mg three times daily, last dose before 4 PM), fludrocortisone (0.1–0.2 mg daily, caution with fluid retention in cardiac patients), compression stockings, increased salt and fluid intake, slow position changes, elevated head of bed
GI dysmotility (gastroparesis, diarrhea, constipation): Small frequent meals. Metoclopramide for gastroparesis (short-term). Loperamide for diarrhea. Bile acid sequestrants (cholestyramine) if bile acid malabsorption. Octreotide for refractory diarrhea. Dietary modifications with nutrition support.
Urinary dysfunction: Bladder training, timed voiding, intermittent catheterization if needed. Urology referral for retention or incontinence.
Erectile dysfunction: PDE5 inhibitors (sildenafil, tadalafil) — use with extreme caution if orthostatic hypotension is present.

Weight loss and malnutrition are common in hATTR-PN due to GI amyloid deposition and autonomic dysfunction. mBMI (modified BMI = BMI × serum albumin) is used to track nutritional status.

Dietitian referral for all patients
High-calorie, high-protein diet with small frequent meals
Vitamin A supplementation (required with gene-silencing therapies)
Vitamin D and B12 monitoring
Enteral nutrition (feeding tube) may be needed in advanced disease with severe GI dysmotility

What is causing my specific symptoms (pain, dizziness, GI problems)?
Are there medications that can help my neuropathic pain without worsening other symptoms?
How should I manage my orthostatic hypotension safely?
Do I need nutritional support or a dietitian?
Should I see a cardiologist, urologist, or other specialists?
What exercise is safe and beneficial for me?
Are there physical therapy or occupational therapy programs for people with polyneuropathy?

Cardiac Involvement

Many patients with hATTR-PN develop cardiac amyloidosis (cardiomyopathy). Amyloid deposits stiffen the heart walls, leading to diastolic heart failure (the heart cannot relax properly to fill with blood), conduction abnormalities, and arrhythmias. Cardiac disease is the primary determinant of survival in hATTR.

Tafamidis (Vyndamax 61 mg or Vyndaqel 80 mg daily): The only FDA-approved treatment for ATTR cardiomyopathy. Reduces mortality and hospitalizations. Should be started early.
Diuretics: Loop diuretics (furosemide, torsemide) for fluid management. Use carefully — over-diuresis can worsen orthostatic hypotension.
Pacemaker: May be needed for conduction block (common in cardiac ATTR). Prophylactic pacemaker implantation may be considered in patients with progressive conduction disease.
Anticoagulation: Consider in patients with atrial fibrillation (common in cardiac ATTR). ATTR cardiomyopathy creates a prothrombotic environment; anticoagulation threshold may be lower.

Medications to AVOID in ATTR cardiomyopathy:

Digoxin: Binds to amyloid fibrils, increasing risk of toxicity at standard doses
Calcium channel blockers (diltiazem, verapamil): Can cause severe hypotension and heart failure in amyloid cardiomyopathy
Beta-blockers: Use with extreme caution. May be tolerated at low doses but can worsen low cardiac output. Often contraindicated.
ACE inhibitors / ARBs: May worsen hypotension. Use only with careful monitoring.

Do I have cardiac involvement? What does my echocardiogram show?
Should I be on tafamidis for my heart?
Am I at risk for arrhythmia or heart block?
Do I need a pacemaker?
Are any of my current medications unsafe for amyloid cardiomyopathy?
How do we balance managing my heart failure with my orthostatic hypotension?

Liver Transplant

Before gene-silencing therapies were available, liver transplant was the only disease-modifying treatment for hATTR-PN. The liver produces over 95% of circulating TTR, so replacing the liver with a normal donor liver eliminates the source of mutant TTR.

Liver transplant is no longer considered first-line treatment for most patients with hATTR-PN
Gene-silencing therapies have largely replaced transplant because they are effective, less invasive, and avoid transplant-related complications (lifelong immunosuppression, surgical risk, organ shortage)
Liver transplant may still be considered for:
- Young patients (under 40–50) with early-stage Val30Met disease and no cardiac involvement
- Patients who cannot tolerate or do not respond to gene-silencing therapies
- Patients in regions where gene-silencing therapies are not available
Limitations of liver transplant: Cardiac amyloid may continue to progress after transplant (wild-type TTR from the donor liver can deposit on existing amyloid). Eye and CNS amyloid can progress because TTR is also produced locally in the retina and choroid plexus.

Pregnancy, Fertility & Family Planning

Hereditary ATTR is autosomal dominant: each child of an affected parent has a 50% chance of inheriting the TTR variant. Penetrance and age of onset vary (and differ by variant and sometimes by which parent carries it), so inheriting the variant does not guarantee symptoms at a predictable age. Because of this, genetic counseling and cascade testing of at-risk relatives are central.

Genetic counseling & reproductive options. If you carry a TTR variant, a genetic counselor can explain inheritance and options including prenatal testing and preimplantation genetic testing (PGT-M) with IVF to avoid passing on the variant. Cascade testing lets relatives learn their status and start monitoring early.
Vitamin A monitoring with TTR-lowering drugs. Transthyretin carries vitamin A (retinol) in the blood, so the gene silencers (patisiran, vutrisiran, inotersen, eplontersen) lower vitamin A levels. Patients on these drugs are advised to take the recommended daily allowance of vitamin A and have eye (ophthalmology) monitoring. This matters in pregnancy because both too little and too much vitamin A can harm a developing baby — vitamin A management in pregnancy must be individualized with your specialist, and these therapies’ safety in pregnancy is not well established.
Discuss therapy before conceiving. There are limited human pregnancy data for TTR silencers and stabilizers. Whether to continue, pause, or switch therapy before and during pregnancy is an individualized decision with your neurology/amyloidosis team — do not stop or change treatment on your own.
Team-based care. A maternal-fetal medicine (high-risk obstetrics) specialist should co-manage pregnancy together with your amyloidosis team, with attention to cardiac and autonomic involvement where present.

Questions to ask your doctor:

What is the chance I could pass this on, and would genetic counseling or PGT help us plan?
If I am on a TTR-lowering medication, how should vitamin A be managed before and during pregnancy?
Should I continue, pause, or change my therapy if I want to become pregnant?
Who should be on my care team, and how will my heart and nerves be monitored during pregnancy?

Clinical Trials — Finding and Enrolling

Clinical trials continue to advance treatment for hATTR-PN. Several novel approaches are in development, including gene editing and next-generation gene silencers. Trials are particularly important for patients who may not respond adequately to current therapies.

Trial / Agent	Mechanism	Population	NCT Number
NTLA-2001 (Intellia)	CRISPR/Cas9 in vivo gene editing — single IV infusion to knock out TTR gene	hATTR with polyneuropathy and/or cardiomyopathy	NCT04601051
HELIOS-B (vutrisiran for cardiomyopathy)	RNAi (vutrisiran) in ATTR cardiomyopathy	ATTR cardiomyopathy (hereditary and wild-type)	NCT04153149
CARDIO-TTRansform (eplontersen for cardiomyopathy)	ASO (eplontersen) in ATTR cardiomyopathy	ATTR cardiomyopathy (hereditary and wild-type)	NCT04136171
APOLLO-B (patisiran for cardiomyopathy)	RNAi (patisiran) in ATTR cardiomyopathy	ATTR cardiomyopathy	NCT03997383
ATTRibute-CM (acoramidis / AG10)	Next-generation TTR stabilizer (FDA-approved for ATTR-CM, Nov 2024)	ATTR cardiomyopathy	NCT03860935

Note on NTLA-2001: This is a particularly exciting approach. Early-phase data showed that a single IV infusion of CRISPR-based gene editing reduced serum TTR by approximately 90% at the highest dose. If long-term safety and efficacy are confirmed, this could be a one-time treatment for hATTR. Verify current enrollment status on ClinicalTrials.gov before pursuing.

ClinicalTrials.gov (clinicaltrials.gov): Search for “hereditary ATTR amyloidosis polyneuropathy”
Amyloidosis Research Consortium (ARC): arci.org — Information about ongoing trials and patient resources
Amyloidosis Foundation: amyloidosis.org — Patient support and trial information
Your amyloidosis center: Academic centers often have open trials not widely advertised. Ask your specialist directly.

International Access & Regulatory Landscape

hATTR therapy approvals vary by country. Some therapies approved in one region may not yet be available in another.

Drug	US FDA	EMA (Europe)	PMDA (Japan)	Health Canada	Notes
Patisiran (Onpattro)	2018 (hATTR-PN)	2018	2019	2019	First RNAi drug approved for any disease
Vutrisiran (Amvuttra)	2022 (hATTR-PN); 2025 (ATTR-CM)	2022	2022	2023	Quarterly SC injection. FDA-approved for both polyneuropathy (2022) and cardiomyopathy (Mar 2025)
Inotersen (Tegsedi)	2018 (hATTR-PN)	2018	Not approved	2018	Boxed warning for thrombocytopenia; being superseded by eplontersen
Eplontersen (Wainua)	2023 (hATTR-PN)	2024	Under review	Under review	Monthly SC. No platelet monitoring
Tafamidis (Vyndaqel/Vyndamax)	2019 (cardiomyopathy); EU 2011 (PN)	2011 (hATTR-PN stage 1); 2020 (CM)	2019	2020	EMA approved for PN before US; FDA only for cardiomyopathy
Diflunisal	Off-label only	Off-label	Off-label	Off-label	NSAID; randomized trial supports use; availability varies

Canadian hATTR-PN Guidelines (Can J Neurol Sci, 2022; epub 2021): Canadian guidelines for hereditary transthyretin amyloidosis polyneuropathy management
Expert / European consensus statements: International expert recommendations for diagnosis and management (e.g., Adams et al.)
NICE (UK): Technology appraisals for patisiran and inotersen/tafamidis
PMDA (Japan): Japan has historical expertise due to endemic Val30Met population
INSA (Portugal): Portuguese national amyloidosis reference center

Failed & De-Adopted Therapies

Knowing what has been tried and did not work or is no longer recommended helps patients evaluate new options and avoid outdated approaches.

DE-ADOPTED AS FIRST-LINE Liver transplant was the standard of care from the 1990s until gene-silencing therapies became available in 2018. While transplant eliminates mutant TTR from the liver, it requires lifelong immunosuppression, carries surgical risk, requires organ availability, and does not prevent cardiac or ocular amyloid progression (wild-type TTR from the donor liver can deposit on existing amyloid scaffolds). Gene-silencing therapies are now preferred first-line for most patients.

UNPROVEN This combination was proposed as an amyloid-disrupting therapy based on preclinical data. Small open-label studies suggested possible benefit, but no randomized controlled trial has demonstrated efficacy. A phase 3 trial has not been completed. This combination should not be used as a substitute for proven gene-silencing therapies. Some patients use it as an adjunct, but evidence remains insufficient.

FAILED Revusiran was an early GalNAc-conjugated RNAi therapy developed by Alnylam. The ENDEAVOUR trial was halted in 2016 due to an imbalance in deaths in the treatment arm, likely related to the chemical modification platform used. This led to the development of improved chemistry platforms used in vutrisiran. Revusiran is not available.

DISCONTINUED GSK developed a two-step approach: miridesap to deplete serum amyloid P component (SAP) followed by dezamizumab antibody to target and remove amyloid deposits. Early results showed amyloid removal on imaging. However, GSK discontinued development due to manufacturing and commercial challenges, not efficacy concerns. This approach is no longer in development.

Why this matters: If someone suggests one of these therapies, you now know its history. Always ask your specialist: “Has this been tested in a randomized controlled trial for hATTR, and what were the results?”

Is liver transplant appropriate for my situation, or are drug therapies preferred?
Is gene-editing (CRISPR) being studied at your center?
Are there clinical trials open for my specific mutation?
If my current therapy is not working well enough, what are the next options?
How do you define treatment success — stabilization or improvement?
Should I be getting regular cardiac monitoring even if my symptoms are mainly neurological?

Specialty Centers

hATTR-PN is rare and frequently misdiagnosed. Treatment at or in consultation with a center that has amyloidosis expertise leads to faster diagnosis, more coordinated care, and access to clinical trials. A second opinion from an amyloidosis center is strongly recommended.

No endorsement. Listing a center here does not constitute an endorsement or recommendation. Trouvera has no financial relationship with any medical center listed unless explicitly disclosed. Patients should evaluate centers based on their own needs and in consultation with their medical team.

University of Utah — Peripheral Nerve / Amyloidosis Program

Academic neurology program with peripheral nerve and amyloidosis expertise

Location: 175 N Medical Dr, Salt Lake City, UT 84132
Phone: 801-581-2121
Programs: Peripheral Nerve Division, neuromuscular diagnostics, EMG/NCS, skin biopsy for small fiber neuropathy, autonomic testing, genetic testing and counseling, clinical trials for polyneuropathy. Collaboration with Huntsman Cancer Institute for hematologic amyloidosis.

Huntsman Cancer Institute (HCI) — University of Utah

Location: 2000 Circle of Hope Dr, Salt Lake City, UT 84112
Phone: 801-585-0303
Programs: NCI-designated Comprehensive Cancer Center. While primarily oncology-focused, provides multidisciplinary amyloidosis care coordination including cardiac evaluation, hematology consultation (for AL amyloidosis differential), and clinical trials infrastructure.

Intermountain Health — Neurology

Location: Multiple locations, Salt Lake City, UT
Phone: 801-442-2000
Programs: Neurology and neuromuscular services. Peripheral neuropathy evaluation. Can initiate hATTR workup and refer to specialized amyloidosis centers for confirmed cases.

How to choose. University of Utah Peripheral Nerve/Amyloidosis Program = Academic center with specialized neuromuscular and amyloidosis diagnostics, genetic counseling, and clinical trial access. Intermountain Health = Community neurology with broad access, can initiate evaluation and coordinate referrals.

Information verified May 2026. Availability changes — confirm with each institution directly.

Mayo Clinic — Amyloidosis Program

Location: Rochester, MN · Phone: 507-538-3270
One of the world’s largest and most experienced amyloidosis programs. Comprehensive TTR amyloidosis care including neurology, cardiology, genetic counseling, tissue typing, and clinical trials. Published many landmark studies in ATTR amyloidosis.

Boston University Amyloidosis Center

Location: Boston, MA · Phone: 617-358-9560
One of the pioneering amyloidosis programs. Comprehensive TTR and AL amyloidosis care. Tissue typing by mass spectrometry. Active clinical trials including gene-silencing therapies and CRISPR gene editing.

Columbia University — Amyloidosis Program

Location: New York, NY · Phone: 212-305-9770
Multidisciplinary amyloidosis center with neurology, cardiology, and genetics expertise. Active in hATTR clinical trials.

Stanford Amyloid Center

Location: Palo Alto, CA · Phone: 650-498-6000
Comprehensive amyloidosis program. Neurology, cardiology, and transplant services. Clinical trials for ATTR amyloidosis.

Cleveland Clinic — Amyloidosis Multidisciplinary Practice

Location: Cleveland, OH · Phone: 866-588-2264
Multidisciplinary amyloidosis team. Neurology, cardiology, hematology. Active trial participation.

VA Salt Lake City Health Care System (George E. Wahlen VAMC)

Location: 500 Foothill Dr, Salt Lake City, UT 84148
Phone: 801-582-1565
Neurology services with peripheral neuropathy evaluation. Veterans with suspected hATTR can be referred to the University of Utah amyloidosis program or Mayo Clinic through VA Community Care.

Primary Children’s Hospital (for pediatric/young adult cases)

Location: 100 N Mario Capecchi Dr, Salt Lake City, UT 84113
Phone: 801-662-1000
Pediatric neurology and genetics. Relevant for early-onset hATTR cases and genetic counseling for young family members.

VA Neurology Care: Veterans may access amyloidosis specialty care at affiliated academic centers through Community Care referral. Contact the local VA oncology or neurology team, or the Patient Advocate for referral coordination.
VA Community Care: 1-877-881-7618

University Health Network — Toronto General Hospital

Location: Toronto, ON
Phone: 416-340-4800
Amyloidosis clinic with neurology and cardiology. Genetic testing and counseling. Active in hATTR clinical trials.

McGill University Health Centre

Location: Montréal, QC
Phone: 514-934-1934
Peripheral nerve clinic with amyloidosis expertise.

Canadian Amyloidosis Support Network: Resources and peer support for Canadian patients

International Centers of Excellence for hATTR Amyloidosis

Centro Hospitalar Universitário do Porto (Unidade Corino de Andrade), Portugal: The world’s first and most experienced hATTR center. Identified Val30Met amyloidosis in 1952. National reference center for Portuguese patients.
Umeå University Hospital, Sweden: Leading center for the Swedish Val30Met endemic population. Published landmark natural history studies.
Shinshu University Hospital, Matsumoto, Japan: Japanese reference center for hATTR. Extensive experience with liver transplant and gene-silencing therapies.
National Amyloidosis Centre, University College London, UK: Europe’s largest amyloidosis center. SAP scintigraphy (unique to UCL). All ATTR subtypes.
Hôpital Bicêtre / CHU Henri Mondor, Paris, France: French national reference center for amyloidosis neuropathies (NNERF).

Caregiver Guidance

Caring for someone with hATTR-PN presents unique challenges. The progressive nature of the neuropathy, autonomic dysfunction, and potential cardiac involvement require ongoing adaptation.

Sensory neuropathy and orthostatic hypotension greatly increase fall risk. Remove loose rugs, install grab bars in bathrooms, ensure good lighting.
Foot drop (from motor neuropathy) may require ankle-foot orthoses (AFOs). Refer to orthotics.
Physical therapy for gait training, balance exercises, and strengthening is essential.
As mobility declines, occupational therapy for adaptive equipment (walkers, wheelchairs, home modifications) becomes important.

Orthostatic hypotension: Help the patient rise slowly from sitting/lying. Have them sit on the edge of the bed before standing. Keep water and salty snacks accessible. Compression garments help.
GI symptoms: Plan small, frequent meals. Keep a food diary to identify triggers. Ensure adequate hydration. Monitor weight weekly.
Temperature regulation: Many patients have impaired sweating. Avoid overheating. Use cooling vests in hot weather.

hATTR-PN is a genetic disease, which adds the burden of knowing it may affect your children. Genetic counseling provides support for these concerns.
Connect with patient organizations: Amyloidosis Foundation (amyloidosis.org), Amyloidosis Research Consortium (arci.org), hATTR Amyloidosis Association
Online patient communities provide peer support from others who understand the disease
Caregiver burnout is real. Accept help. Take breaks. Your health matters too.

Glossary

Amyloid: Misfolded protein fibers that deposit in tissues and organs, causing damage. In hATTR, the amyloid is made of misfolded transthyretin protein.
Antisense oligonucleotide (ASO): A synthetic strand of nucleotides that binds to messenger RNA and triggers its degradation, preventing protein production. Inotersen and eplontersen are ASOs.
Autosomal dominant: A pattern of inheritance where only one copy of a mutated gene (from one parent) is needed to cause the condition. Each child of an affected parent has a 50% chance of inheriting the mutation.
Autonomic neuropathy: Damage to nerves that control involuntary body functions: blood pressure, heart rate, digestion, bladder, sweating, and sexual function.
Cardiomyopathy: Disease of the heart muscle. In ATTR amyloidosis, amyloid deposits stiffen the heart walls, impairing filling and pumping.
Congo red stain: A dye used to identify amyloid in tissue biopsies. Amyloid shows apple-green birefringence under polarized light.
CRISPR/Cas9: A gene-editing technology that can precisely cut and modify DNA. NTLA-2001 uses CRISPR to knock out the TTR gene in the liver.
FAP (Familial Amyloid Polyneuropathy): The historical name for hereditary ATTR amyloidosis with polyneuropathy. The FAP staging system (stages 1–3) is still widely used.
GalNAc conjugation: A chemical targeting technology that directs drugs to liver cells via the asialoglycoprotein receptor. Used in vutrisiran and eplontersen.
mBMI (Modified BMI): BMI multiplied by serum albumin. Used to track nutritional status in hATTR patients, where weight loss is common and prognostically significant.
mNIS+7 (Modified Neuropathy Impairment Score + 7): A composite score used in clinical trials to measure neuropathy severity, combining neurological examination findings with nerve conduction, QST, and heart rate variability. Lower is better.
Orthostatic hypotension: A drop in blood pressure upon standing, causing dizziness, lightheadedness, or fainting. Common in hATTR-PN due to autonomic neuropathy.
Penetrance: The proportion of people carrying a genetic mutation who actually develop the disease. hATTR has incomplete penetrance — not all carriers become symptomatic.
Polyneuropathy: Disease affecting multiple peripheral nerves simultaneously, typically causing numbness, tingling, pain, and weakness in the feet and hands that progresses upward.
RNA interference (RNAi): A natural cellular process where small RNA molecules silence specific genes. Patisiran and vutrisiran use synthetic siRNA to silence TTR mRNA.
Small fiber neuropathy: Damage to small nerve fibers (unmyelinated C-fibers and thinly myelinated A-delta fibers) causing pain, temperature sensing loss, and autonomic dysfunction. Often the earliest neurological finding in hATTR-PN.
Technetium pyrophosphate (PYP) scan: A nuclear imaging test that detects ATTR amyloid deposits in the heart. Highly specific for ATTR cardiac amyloidosis.
TTR (Transthyretin): A protein made primarily by the liver that transports thyroid hormone and vitamin A. Mutations in the TTR gene cause the protein to misfold and form amyloid.
TTR stabilizer: A drug that binds to the TTR protein tetramer and prevents it from falling apart and misfolding. Tafamidis and diflunisal are TTR stabilizers.
Val30Met (V30M): The most common TTR mutation worldwide. Endemic in Portugal, Sweden, Japan. Primarily causes polyneuropathy.
Wild-type ATTR (wtATTR): ATTR amyloidosis caused by normal (non-mutated) TTR protein that misfolds with aging. Not hereditary. Primarily causes cardiomyopathy in elderly men.

Sources and Further Reading

This guide draws on published medical literature, clinical trial records, and the work of physicians treating hATTR amyloidosis across multiple countries. Key sources are listed below.

Primary Resources

PubMed (pubmed.ncbi.nlm.nih.gov) — Free public database of medical research
ClinicalTrials.gov (clinicaltrials.gov) — Authoritative registry of clinical trials
Amyloidosis Foundation (amyloidosis.org) — Patient education, support groups, and clinical trial information
Amyloidosis Research Consortium (ARC) (arci.org) — Research advocacy and patient resources
National Organization for Rare Disorders (NORD) (rarediseases.org) — hATTR amyloidosis information
FDA MedWatch (fda.gov/medwatch) — Report adverse events from any medication

Key Guideline and Trial References

Canadian hATTR-PN Guidelines: Alcantara M, Mezei MM, Baker SK, et al. Canadian guidelines for hereditary transthyretin amyloidosis polyneuropathy management. Can J Neurol Sci. 2022;49(1):7–18. (Plus expert consensus, e.g., Adams D, et al. J Neurol. 2021.)
APOLLO: Adams D, Gonzalez-Duarte A, O'Riordan WD, et al. Patisiran, an RNAi therapeutic, for hereditary transthyretin amyloidosis. N Engl J Med. 2018;379(1):11–21. (NCT01960348)
NEURO-TTR: Benson MD, Waddington-Cruz M, Berk JL, et al. Inotersen treatment for patients with hereditary transthyretin amyloidosis. N Engl J Med. 2018;379(1):22–31. (NCT01737398)
HELIOS-A: Adams D, Tournev IL, Taylor MS, et al. Efficacy and safety of vutrisiran for hereditary transthyretin-mediated amyloidosis with polyneuropathy. Amyloid. 2023;30(1):1–14. (NCT03759379)
NEURO-TTRansform: Coelho T, Marques W Jr, Dasgupta NR, et al. Eplontersen for hereditary transthyretin amyloidosis with polyneuropathy. JAMA. 2023;330(15):1448–1458. (NCT04136184)
ATTR-ACT: Maurer MS, Schwartz JH, Gundapaneni B, et al. Tafamidis treatment for patients with transthyretin amyloid cardiomyopathy. N Engl J Med. 2018;379(11):1007–1016. (NCT01994889)
Diflunisal trial: Berk JL, Suhr OB, Obici L, et al. Repurposing diflunisal for familial amyloid polyneuropathy. JAMA. 2013;310(24):2658–2667. (NCT00294671)

External links notice: Links to government agencies, academic institutions, and private organizations are provided for informational convenience. Linking does not constitute endorsement by Trouvera, and we cannot attest to the accuracy of external content. You will be subject to the destination site’s privacy policy when you leave this site.

A practical test for any online claim: If a website is making a claim about hATTR treatment that does not appear anywhere in PubMed or AAN/European guidelines, that should be a significant warning sign.

What This Guide Does Not Know

An honest guide names its own limits:

This guide cannot diagnose or treat anyone. It does not know your mutation, disease stage, organ involvement, or personal circumstances. Only your medical team can build an actual treatment plan.
hATTR-PN treatment is evolving rapidly. New approvals, trial results, and guideline updates occur frequently. Every time-sensitive fact should be re-verified with your team, on FDA.gov, and on ClinicalTrials.gov.
Drug approvals and availability vary by country. This guide focuses primarily on FDA-approved therapies. Access differs in Europe, Japan, Canada, and other regions.
Individual outcomes cannot be predicted. The same mutation can cause different severity in different family members. Treatment response varies.
This disease is rare. Many neurologists will see only a few hATTR patients in their career. Referral to an amyloidosis center for at least a second opinion is often the single highest-value step a patient can take.

A final word. hATTR-PN is no longer an untreatable disease. The therapies approved since 2018 represent one of the most dramatic transformations in rare disease medicine. Patisiran, vutrisiran, inotersen, eplontersen, and tafamidis give patients real hope for stabilization and even improvement. The key is early diagnosis and early treatment. If you suspect hATTR, get tested. If you are a carrier, get monitored. If you have symptoms, get treated. Bring this guide to your appointments. You are not alone. Help is real. Use it.