SEVERE CHILDHOOD AUTOSOMAL RECESSIVE MUSCULAR-DYSTROPHY WITH THE DEFICIENCY OF THE 50 KDA DYSTROPHIN-ASSOCIATED GLYCOPROTEIN MAPS TO CHROMOSOME-13Q12

We have recently demonstrated the specific deficiency for the 50 kDa d ystrophin-associated glycoprotrein (50DAG) in Algerian patients afflic ted with severe childhood autosomal recessive muscular dystrophy with DMD-like phenotype (SCARMD). A similar disease affecting Tunisian pati ents was linked to chromosome 13q but the status of the 50DAG was not investigated. Here we show by linkage analysis of Algerian families th at the genetic defect which leads, either directly or indirectly, to t he deficiency of the 50DAG in skeletal muscle is localized to the prox imal part of chromosome 13q. We have not found any evidence of genetic heterogeneity among the thirteen families studied. It remains to be d emonstrated whether the 50DAG gene maps at 13q12, and to determine if it is mutated in this disease.