A 10-YEAR EXPERIENCE OF MOLECULAR TESTING IN DMD/BMD MUSCULAR DYSTROPHIES IN GREECE

Objectives: Molecular analysis of patients with dystrophinopathies in Greece.

Methods: Our Department is a referral centre for DMD/BMD in Greece since 1990. Diagnosis and disease prevention is offered via prenatal diagnosis and carrier detection mainly performed with routine protocols (multiplex PCR for deletions and linkage analysis for carrier detection). During the last 10 years 415 non-related patients (400 of Greek origin and 15 Albanian) were referred for DMD/BMD testing.

Results: Out of these 415 patients 83 cases were characterized as familial based on the family pedigree or the molecular analysis results. 186 of the 415 patients, showed a deletion concerning one or more exons (32 on the 5' end, 5 along and 149 on the 3'end of the gene). Two cases were of great interest since in the first a very mild phenotype was observed in the patient carrying a large deletion (exons 4–44) concerning 51% of the gene and in the second 2 DMD patients carrying different alterations were related through paternal lines. In addition, 10 point mutations and 5 duplications were recently identified performing new protocols on a research basis. In parallel, 116 prenatal tests were performed and 1510 individuals were studied for carrier detection. In the case of 6 families where the affected individual was diseased, carrier detection was based on the haplotypes of healthy male individuals. Of the remaining 207 patients, 50 are considered as DMD/BMD patients as confirmed by muscle biopsy while the rest 157 require further investigation both on clinical and molecular basis.

Conclusion: In this study deletions represent only the 45% of cases – instead of 65% mentioned in the literature- finding which is probably due to the fact that, within this sample, patients with other muscular dystrophies are also included.