[Genetic analysis of Spanish families with myotonic dystrophy]

Myotonic dystrophy (MD) is the most common form of muscular dystrophy in adult life, with a clinical prevalence of 5.5/100,000, being the gene prevalence of 13.5. The disease is autosomal dominant with variable expressivity, existing a congenital form with a severe prognosis. Recent genetic studies revealed that the DM gene is localized in the chromosome's 19 proximal long arm and with recombinant DNA techniques, several polymorphic markers have been isolated near the gene, the closet being Apo-CII, LDR 152 and p 4.1. We have studied clinically, electrophysiologically and by genetic analysis 6 families with 32 individuals. We have diagnosed the disease in 16 individuals and after the molecular analysis, the DM gene was totally excluded in 6 clinically healthy individuals. In our preliminary study, the use of Msp I/p 4.1, Bgl II/LDR 152 y Ban I, Bgl I, Taq I/Apo-CII c-DNA and genomic was found the most informative combination. These molecular analysis seem to be very useful as a complement to the diagnosis of myotonic dystrophy.