[Screening for heterozygotes in a large family suffering from Steinert's disease with varying clinical manifestations (author's transl)].
Starting with 4 probands, our study for the early detection of heterozygotes enabled us to investigate a family suffering from myotonic dystrophy, through 8 generations. Out of 274 family members, 209 are still living, 101 of whom were examined by us personally. We discovered, in all, 12 patients with Steinert's disease (one of which was a childhood case), 14 with a "forme fruste" (two of which were infantile cases) and 2 patients with only a myotonic cataract. The clinical picture varied a great deal amongst the patients, but showed in general a rather benign evolution. With respect to diagnostic methods, most of the 24 secondary cases were detected through clinical examination preceded by a good case history (6 out of the 8 classical forms, and all the 14 "formes frustes"). Slit lamp examination was indispensable for the recognition of the first changes in the lenses of two young adults and, likewise, for the detection of two isolated myotonic cataracts. The electromyography showed characteristic anomalies in 3 patients; in addition, non-specific alterations existed in 3 other patients who showed only slight signs of the disease. Neither the gammaglobulins nor the ABH secretion factors were of any diagnostic aid in this family. Our investigation is relevant in the context of the prevention of hereditary conditions, in particular Steinert's disease. Indeed, owing to the early recognition of the heterozygotes, an adequate genetic prognosis can be given in due time to the family members at risk.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002386:Cataract / Q000235:genetics; D005260:Female; D005799:Genes, Dominant; D006580:Genetic Carrier Screening; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000175:diagnosis / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D011296:Prenatal Diagnosis
Depistage des heterozygotes dans une grande famille atteinte de maladie de Steinert aux manifestations cliniques variees.