Evidence of left ventricular dysfunction in children with merosin-deficient congenital muscular dystrophy

Background Deficiency of the sarcolemmal protein dystrophin has been linked to dilated cardiomyopathy. some children with congenital muscular dystrophy have a deficiency of the laminin alpha(2) chain of merosin, an extracellular matrix protein linked to dystrophin through a group of glycoproteins. it has been shown that deficiency in one of these glycoproteins is responsible for muscular dystrophy and dilated cardiomyopathy. Children with laminin cia deficiency may be at risk for development of cardiomyopathy. Methods and Results We studied the cardiac function of a cohort of 16 children with congenital muscular dystrophy by using 2-dimensional echocardiography. The expression of the laminin alpha(2) of merosin in the patients was determined on a skin or muscle biopsy. Two of 6 merosin-deficient children had an election fraction <40%. The average ejection fraction of the merosin-deficient children was 43% +/- 11%, which was significantly lower than the merosin-positive children (53% +/- 5%, P = .03). Conclusions This study suggests that a deficiency of laminin alpha(2) can give rise to dilated cardiomyopathy, supporting the idea that defects of dystrophin, or of associated proteins, can cause dilated cardiomyopathy in addition to muscular dystrophy.