FREQUENCY OF MYOTONIC-DYSTROPHY GENE CARRIERS IN CATARACT PATIENTS

DNA samples from 231 unselected patients with cataracts were studied t o determine the frequency of the DM mutation in cataract patients. A p revious epidemiological study established a high prevalence of DM in t he population of Guipuzcoa (Basque Country, Spain), 26.5 cases/100 000 . We have found two carriers (0.9%) of the DM mutation in patients who are not related to any previously known DM family. The screening of t he DM mutation in cataract patients should be restricted to young pati ents or people with multicoloured and iridescent opacities, in which t he risk of carrying the DM premutation could be higher. Our results su ggest that subjects with 38 to 80 repeats could constitute the genetic reservoir of the DM mutation.