Transthyretin amyloidosis (ATTR) is when a blood protein called transthyretin falls apart, misfolds and builds up in the heart or the nerves. It can be inherited through a typo in the TTR gene, or come with age in people whose gene is normal. Three medicines are now approved for the heart form.
Transthyretin amyloidosis (ATTR) starts with a protein your liver makes every day. Transthyretin carries a thyroid hormone and vitamin A around the blood, and it normally travels as a set of four pieces held together. When the set falls apart, the loose pieces fold the wrong way and stick together into fibres called amyloid. Over years those fibres pile up in the heart muscle, making it thick and stiff, or along the nerves.
In hereditary ATTR, a typo in the TTR gene makes the protein less stable, so it falls apart more easily. One copy of the typo is enough, so each child of a carrier has an even chance of inheriting it. But carrying it is not the same as being ill: many carriers never are.
In wild-type ATTR, the gene is normal. The protein simply becomes less steady with age, and the disease shows up late in life. It is the more common form among heart patients: in the main trial of the first heart medicine, 76% of patients had it.
The best-known heart typo is V122I, at rs76992529. About 4% of Black Americans carry it. A study that followed 3,856 Black Americans for 21.5 years found that carriers had a higher risk of heart failure (hazard ratio 1.47), yet only 7% of the carriers who had a heart scan showed clear signs of amyloid heart disease. The typo raises the risk; it does not decide the outcome.
Stabilisers hold the four pieces together so they cannot fall apart: tafamidis (Vyndaqel, Vyndamax) and acoramidis (Attruby), both pills. A silencer turns down how much transthyretin the liver makes in the first place: vutrisiran (Amvuttra), an injection every 3 months.
Each was tested against placebo in a large trial: tafamidis in 441 patients over 30 months, acoramidis in 632 patients over 30 months, and vutrisiran in 655 patients for up to 36 months. All three did better than placebo on outcomes that included death and heart-related hospital stays.
For the heart, not directly: all three medicines are approved whether the disease is hereditary or wild-type. Genotype matters in two other places. Vutrisiran is also approved for the nerve damage of hereditary ATTR, which needs a TTR typo. And finding a typo tells your family something: brothers, sisters and children can then be tested too.
ATTR is diagnosed by a heart or nerve specialist, not from a genotype. Carrying a TTR typo, V122I included, does not mean you have the disease or will get it, and nothing on this page is a reason to start, stop or change any medicine.
Doctors usually start looking for ATTR when the heart has become thick and stiff and is failing. A different kind of amyloid, made from pieces of antibodies (AL amyloidosis), can look the same on a scan but is treated completely differently, so it has to be ruled out.
Once ATTR is confirmed, a genetic test of TTR tells the two forms apart. A typo makes it hereditary, and relatives can then be offered testing. Vutrisiran lowers vitamin A in the blood, which is why its label advises a daily vitamin A supplement at the recommended amount.
What a 23andMe/AncestryDNA export or raw VCF can and can't tell you about Transthyretin Amyloidosis (ATTR) comes down to these specific, well-studied positions — not a diagnosis.
Research-derived gene–drug associations only — not a prescription, dosing guide, or medical advice. Always follow your prescriber's guidance.
| Gene | Drug | What the research shows |
|---|---|---|
| TTR | Tafamidis | Tafamidis (Vyndaqel, Vyndamax) is a stabiliser: it holds the four pieces of transthyretin together so they cannot fall apart and turn into amyloid. It is a pill taken once a day, approved in the US since 2019 for the heart form of ATTR, whether hereditary or wild-type, so your genotype does not decide whether you can take it. In its main trial of 441 patients over 30 months, fewer people died or were admitted to hospital for their heart than on placebo. Whether to take it is decided with a specialist, and nothing here is a reason to start, stop or change a medicine. (ATTR-ACT (Maurer MS et al., NEJM 2018, PMID 30145929); VYNDAQEL/VYNDAMAX US prescribing information (DailyMed).) |
| TTR | Acoramidis | Acoramidis (Attruby) is also a stabiliser, a pill taken twice a day, approved in the US in 2024 for the heart form of ATTR, wild-type or hereditary. In its main trial of 632 patients over 30 months, it did better than placebo on a combined measure of death, heart-related hospital stays and heart function. Whether to take it is decided with a specialist, and nothing here is a reason to start, stop or change a medicine. (ATTRibute-CM (Gillmore JD et al., NEJM 2024, PMID 38197816); ATTRUBY US prescribing information, revised 6/2026 (DailyMed).) |
| TTR | Vutrisiran | Vutrisiran (Amvuttra) works differently: it is a silencer that tells the liver to make less transthyretin in the first place. It is an injection given by a health professional every 3 months. In the US it is approved for the heart form of ATTR, wild-type or hereditary, and for the nerve damage of hereditary ATTR, which does need a TTR variant. In its heart trial of 655 patients, it lowered the risk of death and heart events (hazard ratio 0.72). Its label also advises a daily vitamin A supplement at the recommended amount. Whether to take it is decided with a specialist, and nothing here is a reason to start, stop or change a medicine. (HELIOS-B (Fontana M et al., NEJM 2025, PMID 39213194); AMVUTTRA US prescribing information (DailyMed).) |
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Transthyretin Amyloidosis (ATTR). MyGeneLog™. https://www.mygenelog.com/conditions/transthyretin-amyloidosis
It is a disease in which transthyretin, a protein made by the liver, falls apart, misfolds and builds up as amyloid in the heart or the nerves. In the heart it makes the muscle thick and stiff, which leads to heart failure.
Sometimes. Hereditary ATTR comes from a typo in the TTR gene, and one copy is enough: each child of a carrier has an even chance of inheriting it. Wild-type ATTR, the more common form among heart patients, is not inherited and comes with age.
V122I (rs76992529) is a TTR typo carried by about 4% of Black Americans. It raises the risk of heart failure, but most carriers never show clear amyloid heart disease.
Three are approved in the US: tafamidis and acoramidis, pills that hold transthyretin together, and vutrisiran, an injection every 3 months that makes the liver produce less of it. All three are approved for both the hereditary and the wild-type form.
That is a decision for you and a doctor or genetic counsellor. A test matters most once ATTR has been diagnosed, because a typo means your relatives can be tested too. A positive result on its own does not mean you will become ill.
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