A protein disease almost everyone gets — but doctors rarely catch
Nearly every older person has it in some form: a protein that slowly misfolds and accumulates in the heart and other organs.
Transthyretin is a protein the liver produces to transport hormones and vitamin A through the bloodstream. But like a handful of other proteins, it has a tendency — particularly in older age — to misfold. That misfolding leads to clumping: amyloid, an insoluble plaque that lodges in tissue. In the heart, that buildup creates a thickened, stiff muscle that pumps blood less and less efficiently — heart failure that looks, at first glance, indistinguishable from other forms of heart failure.
The medical system treats this condition as rare. That framing fits the hereditary variant, where a mutation in the transthyretin gene makes the protein extra unstable and causes problems as early as middle age. But the so-called wild type — the non-inherited form that arises simply from aging — is found at autopsy in a quarter to half of people over eighty. Almost none of them had ever been diagnosed.
Long-term data offer grounds for optimism
A new publication presents long-term efficacy data on treatments that address the amyloid problem directly. The first category are stabilizers: drugs like tafamidis that lock the transthyretin protein into its correct shape, preventing it from misfolding and aggregating. The second category are silencers: RNA-based therapies like patisiran or vutrisiran that dramatically reduce how much of the protein the liver produces in the first place. Both approaches show favorable effects on survival and cardiac function in the data — provided treatment starts early enough.
That caveat — early enough — is where the problem lies. Transthyretin amyloidosis has an insidious onset. Symptoms like breathlessness, fatigue, carpal tunnel syndrome, or spinal canal narrowing are non-specific and routinely attributed to other causes. A blood test exists but is rarely ordered. A specialized cardiac scan using radioactive tracers — scintigraphy — can confirm the diagnosis but is not universally available or embedded in standard diagnostic pathways.
A universal disease wearing a rare-disease label
The debate these data spark goes beyond the drugs themselves. It raises a fundamental question for the medical system: why is a condition that is physiologically universal — one that affects every aging body in some degree — treated as an edge case deserving attention only when patients are already seriously ill? The researchers behind this publication explicitly call for broader screening in at-risk groups, particularly people over seventy with unexplained cardiac symptoms.
Whether that call is heeded depends partly on economics. Existing treatments are expensive — tafamidis cost over 200,000 dollars per patient per year at launch in the United States. Broader screening would generate more diagnoses and therefore a larger pool of patients eligible for costly treatment. That arithmetic makes policymakers cautious, even as health economic analyses suggest early treatment is cheaper in the long run than managing advanced heart failure. The question of when a universal aging process becomes a treatable disease — and who pays for that transition — remains unresolved.