Myotonic dystrophy type 1 (DM1) is an autosomal dominant, multisystemic disorder caused by expansion of an unstable (CTG)n repeat in the 30 untranslated region of the dystrophia myotonica protein kinase (DMPK) gene on chromosome 19q13.3.Aim
Implementation of a molecular diagnostic method for DM1 in a sample of Egyptian patients.Methods
Molecular analysis of the DMPK gene mutation was carried out using expand long PCR method and polyacrylamide gel electrophoresis.Results
Our study showed an increase in the number of CTG repeat units (above 35 repeat units) in all patients with DM1 (13 probands) and seven family members. The largest expansion found in our group of patients was 299 repeats. The normal individuals did not exceed 35 repeat units. Furthermore, we observed expansion of the enlarged fragment during transmission from one generation to the next.Conclusion
This first report on the molecular diagnosis of DM1 in Egyptian patients. Furthermore, this study emphasizes an important role of genetic testing for early diagnosis, management and proper genetic counseling.