A recent study examined how frequently the V122I genetic variant leads to heart failure in older Black individuals. This research sought to identify how specific genes can influence the development and presentation of transthyretin amyloid cardiomyopathy.
- Transthyretin amyloid cardiomyopathy (ATTR-CM) remains an underdiagnosed cause of heart failure among older individuals.
- The V122I variant, associated with hereditary ATTR-CM, is present in 3.4% of Black individuals in the U.S.
- Among Black individuals with ATTR-CM, 63% had wild-type, and the phenotypic penetrance of V122I-associated ATTR-CM was 39%.
- Genotyping alone may not be enough to diagnose transthyretin amyloid cardiomyopathy in heart failure patients.
The V122I variant of the transthyretin protein, which involves a change from valine to isoleucine at position 122, has long been of interest to medical researchers. This genetic alteration is particularly prevalent among Black populations, making it a focus for some studies on heart health in these communities.
Decoding the Clinical Penetrance of V122I in ATTR-CM
While the link between V122l and ATTR-CM is acknowledged, its exact role and the extent of its impact have remained the subjects of ongoing investigation. A study published in the Journal of the American Heart Association found that the V122I genetic variant was present in 39% of older Black heart failure patients. This finding emphasizes that simply detecting the V122I genetic variant in patients doesn’t necessarily confirm the presence of ATTR-CM.
Comparative Analysis: V122I Carriers vs. Non-Carriers
The study looked at individuals with the V122I variant who had ATTR-CM and those who didn’t. Those with ATTR-CM showed more advanced signs of heart failure. Moreover, V122I individuals with ATTR-CM had a lower prealbumin level as well as lower 6MWD score, ejection fraction, stroke volume, and cardiac output, pointing to changes in the transthyretin protein compared to those without and other heart failure cases.
Navigating ATTR-CM Diagnosis and Treatment
For healthcare professionals, this research underscores that genotype analysis alone may be insufficient in diagnosing ATTR-CM in older Black heart failure patients. Since there are effective treatments for ATTR-CM, it’s crucial to identify it early and accurately. The study suggests that measuring prealbumin levels could also help pinpoint ATTR-CM, especially in those with the V122I genetic variant, giving clinicians another way to diagnose the condition.
Madhani, A., Sabogal, N., Massillon, D., Paul, L., Rodrı́Guez, C., Fine, D., Helmke, S., Winburn, M., Kurian, D., Raiszadeh, F., Teruya, S., Cohn, E., Einstein, A. J., Miller, E. J., Connors, L. H., Maurer, M. S., & Ruberg, F. L. (2023). Clinical penetrance of the transthyretin V122I variant in older Black patients with heart failure: the SCAN‐MP (Screening for Cardiac Amyloidosis with nuclear imaging in Minority Populations) study. Journal of the American Heart Association, 12(15). https://doi.org/10.1161/jaha.122.028973