A systematic review and meta-analysis of genotype-phenotype associations in patients with hypertrophic cardiomyopathy caused by sarcomeric protein mutations

Adult genetic risk screening

Recent advances in genetic analysis especially DNA sequencing technology open a new strategy for adult disease prevention by genetic screening. Physicians presently treat disease pathology with less emphasis on disease risk prevention/reduction. Genetic screening has reduced the incidence of untreatable childhood genetic diseases and improved the care of newborns. The opportunity exists to expand screening programs and reduce the incidence of adult onset diseases via genetic risk identification and disease intervention. This article outlines the approach, challenges, and benefits of such screening for adult genetic disease risks.

Allele-specific silencing of mutant Myh6 transcripts in mice suppresses hypertrophic cardiomyopathy

Dominant mutations in sarcomere proteins such as the myosin heavy chains (MHC) are the leading genetic causes of human hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy. We found that expression of the HCM-causing cardiac MHC gene (Myh6) R403Q mutation in mice can be selectively silenced by an RNA interference (RNAi) cassette delivered by an adeno-associated virus vector. RNAi-transduced MHC(403/+) mice developed neither hypertrophy nor myocardial fibrosis, the pathologic manifestations of HCM, for at least 6 months. Because inhibition of HCM was achieved by only a 25% reduction in the levels of the mutant transcripts, we suggest that the variable clinical phenotype in HCM patients reflects allele-specific expression and that partial silencing of mutant transcripts may have therapeutic benefit.