[Molecular genetics and merosin abnormality in Fukuyama-type congenital muscular dystrophy (FCMD)].

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with brain anomalies. After our initial mapping of FCMD to chromosome 9q31-33, we revealed that the gene lies within a region of < 100 kb containing D9S2107(9q31) by linkage-disequilibrium mapping. A-3 kb insertion was found in most FCMD chromosomes with the founder haplotype. On the other hand, a significant reduction in immunostaining of an extracellular matrix, laminin alpha 2 (merosin) has been noted in the FCMD muscle. Others reported basal lamina abnormalities in the FCMD muscle and brain in electron microscopic examination. We here describe recent advances in molecular genetics of FCMD and abnormalities of the basement membranes.