[Advances in molecular genetics of myotonic dystrophy]

Myotonic dystrophy (DM) is the most common muscular dystrophy affecting adults among Caucasian and Japanese populations, with an average incidence of 12.5 in 100,000 in Caucasians and 5.5 in 100,000 in the Japanese. Recently the DM gene was cloned and characterized showing homology with the family of serine-threonine protein kinase. In DM patients expansion of an unstable trinucleotide CTG repeat, located within the 3' untranslated region of DM kinase gene, is involved. In this review we outline the molecular biological aspects of DM including DNA diagnosis, anticipation, differences between paternal and maternal transmission, founder chromosome and expression of the gene.