Genetic testing, frequent cardiac evaluation in HCM families ‘justified’
MedWire News: Predictive genetic testing and frequent cardiological evaluation for hypertrophic cardiomyopathy (HCM) and risk for sudden cardiac death (SCD) are justified up to advanced age in individuals with a familial mutation, researchers conclude.
They found almost a quarter of asymptomatic carriers of a cardiac myosin binding protein C (MYBPC3) gene mutation was diagnosed with HCM at first cardiological evaluation, while 11% could be at risk for SCD.
To further understanding of the risk for developing HCM and suffering SCD among carriers of a HCM familial mutation, Arthur Wilde (Academic Medical Center, Amsterdam, The Netherlands) and colleagues studied 235 asymptomatic relatives with a proven familial MYPBPC3 mutation identified through active cascade screening in 83 families. The researchers excluded probands and relatives already clinically diagnosed with HCM before genetic testing.
They report that the mean age of mutation carriers was 39.7 years at first cardiological evaluation. A diagnosis of HCM was made in 53 (22.6%) of the carriers at first evaluation; these individuals were significantly older than carriers without left ventricular hypertrophy and significantly less women than men were diagnosed (15.0% vs 31.5%, p=0.003).
Although the mean age at diagnosis did not differ significantly between men (45.5 years) and women (49.7 years), disease penetrance of HCM was lower in women (13% vs 30% at 50 years, p=0.024).
The proportion of mutation carriers diagnosed with HCM did not differ significantly among the different types of MYBPC3 gene mutations identified and disease penetrance was incomplete at 65 years for all the mutation types.
Twenty five (11%) participants had one or more risk factors for SCD and a clinical diagnosis of HCM and could therefore be at high risk for SCD; only three received an implantable cardioverter defibrillator.
Further analysis showed one risk factor was present in 87 carriers and nine had two or more, but the authors remark that “longer follow-up studies are needed to assess if these risk factors are also associated with an increased risk of SCD in carriers without a clinical diagnosis of HCM.”
They conclude in the European Heart Journal: “Our data justify predictive DNA testing in HCM families with a pathogenic mutation, regular cardiological evaluations on the presence of HCM and risk factors for SCD until advanced age.”
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By Caroline Price