Genetic Links to Childhood Heart Hypertrophy Uncovered
Half of presumed sporadic cases have genetic causes
WEDNESDAY, April 9 (HealthDay News) -- Gene mutations may underlie half of all cases of sporadic childhood-onset idiopathic cardiac hypertrophy, and two-thirds of cases in which there is a positive family history, according to study findings published online April 9 in the New England Journal of Medicine.
Hiroyuki Morita, M.D., of Harvard Medical School in Boston, and colleagues studied the contribution of genetics to idiopathic cardiac hypertrophy in 84 children diagnosed with the disease before 15 years of age. The researchers sequenced genes encoding eight sarcomere proteins, mutations of which cause adult-onset hypertrophic cardiomyopathy, and two additional genes, PRKAG2 and LAMP2, mutations of which can cause early-onset hypertrophic cardiomyopathy.
The investigators identified gene mutations in 25 of 51 children without a family history of cardiomyopathy, and in 21 of 33 children with a positive family history. The majority of mutations occurred in genes encoding the sarcomere proteins MYH7 and MYBPC3. Genotyping the parents of 11 children with presumed sporadic disease revealed that four children had new mutations, while seven had inherited mutations, the report indicates. Severity of hypertrophy did not correlate with genetic or familial status.
"Childhood-onset hypertrophy should prompt genetic analyses and family evaluations," the authors conclude.