ClinVar

In 4 affected individuals over 3 generations of a white family of western European descent with left ventricular noncompaction (LVNC5; 613426), Postma et al. (2011) identified heterozygosity for a mutation in exon 39 of the MYH7 gene, resulting in an asn1918-to-lys (N1918K) substitution at a conserved residue. The mutation segregated with disease in the family and was not found in more than 980 ethnically matched control chromosomes. In addition to marked LVNC, the 39-year-old proband exhibited Ebstein anomaly, which was discovered upon evaluation of a cardiac murmur at 3 years of age. She remained asymptomatic despite significant tricuspid regurgitation from age 30 years. She had a mutation-positive son with bicuspid aortic valve and aortic coarctation in whom echocardiography at age 5 years also showed LVNC. Her asymptomatic mutation-positive mother and brother were both found to have LVNC by echocardiography, and her brother also had LV dilation with dysfunction. In an asymptomatic mutation-positive cousin, cardiomyopathy could not be ruled out due to poor imaging quality.