GENETIC EPIDEMIOLOGY OF MYOTONIC-DYSTROPHY IN ISTRIA, CROATIA

Objectives - We evaluated epidemiology of myotonic dystrophy in Istria , Croatia including direct mutation analysis as an additional, specifi c diagnostic criterion. Material and methods - Patients were ascertain ed in the period 1980-1994 from multiple sources under established cli nical criteria with a special reference to congenital and minimal form s of the disease. Additionally, patients and their relatives were eval uated by direct mutation analysis. The prevalence, corrected for under ascertainment, was estimated on July 1, 1989. Results - A total of 33 DM patients from nine families were ascertained. In all families the d iagnosis was confirmed by mutation analysis of the DM gene. After corr ection for underascertainment the prevalence of 18.1/100,000 was calcu lated. Conclusion - One of the highest prevalence estimates of DM in t he populations without evidence of founder effect or genetic isolation was found. Our results imply the importance of ascertainment of patie nts with all forms of DM and utilization of specific diagnostic tests for estimation of genetic epidemiology in DM.