Molecular Analysis of Duchenne Muscular Dystrophy Carriers in Gujarati Population Using Mlpa

Duchenne muscular dystrophy (DMD) is caused by mutation in the dystrophin gene. In DMD, only male carrying the mutated DMD gene is affected while female becomes carrier of the disease because of the X-linked recessive characteristics of the disorder. About one-third of DMD cases show de novo mutations, while the rest are inherited through carrier others or arise from germlinemosaicism. The recognition of female carriers of the DMD gene is vital in order to know the birth of DMD cases. Multiplex Ligation-dependent Probe Amplification (MLPA) is at the most extensively used method for carrier analysis of DMD gene. This study involved analysis of carrier status of only 15 female relatives of affected males. The MLPA analysis of DMD of these cases was carried to screen whole dystrophin gene for heterozygous exon deletions and duplications. The data revealed 83 heterozygous mutations (82 deletions and one duplication), in 12 cases (80%) out of the 15 carriers analysed. Out of 82 heterozygous deletions, 28 (34.15%) deletions were found in the 5’ proximal hot spot region of the DMD gene ranging from exons 1 to 20 and 54 (65.85%) deletions were present in the middistal hot spot region of the gene ranging from exons 40 to 55. In 3 cases (20%), no mutation was identified through MLPA and which require further analysis using direct sequencing for point mutations. This study thus would provide the identification of mutation related to deletion/duplication, for genetic counselling of DMD affected families which is the first report in Gujarati population.