Myotonic dystrophy and chromosome translocation segregating in the same family

We report on a family segregating the myotonic dystrophy (DM) gene and a t(5;8) reciprocal translocation. The DM presented the characteristics typically seen in this disease, i.e. full penetrance, broad expressivity, apparent anticipation in successive generations, presence of a congenital form transmitted by a carrier mother. The family was uninformative for linkage studies with the Lutheran and Secretor loci. The concordance between DM and chromosome translocation in 8 out of 9 individuals at risk was apparently due to chance.