Misclassification of benign variants as pathogenic in multiple patients with African, unspecified ancestry
THURSDAY, Aug. 18, 2016 (HealthDay News) — Variants that have previously been considered causal in hypertrophic cardiomyopathy are often misclassified as pathogenic in patients with African or unspecified ancestry, according to a study published in the Aug. 18 issue of the New England Journal of Medicine.
Arjun K. Manrai, Ph.D., from Harvard Medical School in Boston, and colleagues identified variants that have previously been considered causal in hypertrophic cardiomyopathy and are overrepresented in the general population. These variants were studied in diverse populations and reevaluated in the medical literature. Patient records at a leading genetic-testing laboratory were reviewed for occurrences of these variants.
The researchers found that multiple patients of African or unspecified ancestry received positive reports, with variants misclassified as pathogenic. On subsequent re-categorization, all variants were benign. The most common mutations in the general population were significantly more common among black than white Americans (P < 0.001). These misclassifications probably would have been prevented by inclusion of even small numbers of black Americans in control cohorts.
“These results expand on current guidelines, which recommend the use of ancestry-matched controls to interpret variants,” the authors write. “As additional populations of different ancestry backgrounds are sequenced, we expect variant reclassifications to increase, particularly for ancestry groups that have historically been less well studied.”
Copyright © 2016 HealthDay. All rights reserved.