Cardiomyopathy, Dilated, 1x

A number sign (#) is used with this entry because of evidence that dilated cardiomyopathy-1X (CMD1X) is caused by compound heterozygous mutation in the gene encoding fukutin (FKTN; 607440) on chromosome 9q31.

For a general phenotypic description and a discussion of genetic heterogeneity of dilated cardiomyopathy, see CMD1A (115200).

Clinical Features

Murakami et al. (2006) described 6 Japanese patients from 4 families with dilated cardiomyopathy and mild or no limb-girdle muscle involvement, normal intelligence, and no history of seizures. One patient died at age 12 years from rapidly progressive CMD, and another underwent cardiac transplantation at age 18 years. Skeletal muscle biopsies from the patients showed minimal dystrophic features but altered glycosylation of alpha-dystroglycan (128239) and reduced laminin (see 150240)-binding ability. Cardiac muscle biopsy in 1 patient showed altered glycosylation of alpha-dystroglycan similar to that seen in Fukuyama-type congenital muscular dystrophy (253800).

Molecular Genetics

Murakami et al. (2006) analyzed the FKTN gene in 6 Japanese patients with CMD and mild or no limb-girdle muscle involvement and identified compound heterozygosity in all for a 3-kb retrotransposal insertion (607440.0001) and another missense mutation (607440.0010 or 607440.0011, respectively).