[Neonatal Steinert's disease: apropos of 2 cases in 2 successive generations]

Description of a family who presents two cases of neonatal myotonic dystrophy (Steinert's disease) in two successive generations. The authors summarize the different genetic theories generally advanced; they sum up the antenatal means of diagnostic that is based on the knowledge of linkage of the loci for myotonic dystrophy and Lutheran blood group.