Detection of D4Z4 tandem repeat deletions localized in 4q35 region in facioscapulohumeral muscular dystrophy patients

Facioscapulohumeral Muscular Dystrophy (FSHD), which is characterized by progressive weakness of muscles in the face, shoulder girdle and upper arms, is the third most common muscular disease. FSHD is caused by deletions of the D4Z4 repeats in the 4q35 region. In this autosomal dominantly inherited disease, more than 95% patients have only 1-10 repeats instead of 11-100 repeats observed in healthy controls.In this study, 14 (9 male, 5 female) patients with the average age 39, were handled after the preclinical diagnosis by the Akdeniz University Medical Faculty department of Neurology. DNA was extracted from those patients? peripheral blood, using salting-out method. In order to detect the deletions of D4Z4 tandem repeats at the q35 locus on chromosome 4, Southern blot method was used. Besides, DNA samples which were obtained from 3 healthy individuals were studied as control group. According to our results, even though the number of D4Z4 repeats in control group was found to be in the normal range (more than 11 repeats), 14 FSHD patients? repeat numbers were observed to be under the normal range (less than 11 repeats) as parallel to clinical profile.According to the data we obtained, Southern blot is an applicable strategy for determination of the D4Z4 repeat deletions on chromosome 4. Due to reasons that support the clinical profile and provide definitive diagnosis, also genetic counseling which has great importance; this method can be beneficial when is used in routine practice .Key Words: FSHD, D4Z4 repeats, Southern blot, chromosome 4