Novel Homozygous Pathogenic Mutations of LAMA 2 Gene in patients with congenital muscular dystrophy

The laminin-α2 subunit is a protein that is encoded by the Laminin α 2 gene (LAMA2) which has the role of adhesion (attachment of cells to one another). Genetics consideration showed that mutation in LAMA2 caused a collection of muscle-wasting conditions called Muscular Dystrophy (MD). This disorder causes disconnection of the muscular cells and degeneration of the musculoskeletal system. In this study, we define the molecular consideration of 3 patients with laminin α 2 deficiency by clinical presentations of congenital muscular dystrophy (CMD). In this regard, 65 exons of LAMA2 gene were amplified by Polymerase Chain Reaction (PCR). Also, MLPA and NGS was done for all patients. Because of negativity of NGS, the gene sequence was performed. The results of searching for rearrangements of the LAMA2 gene enabled us to recognize homozygous pathogenic mutations c.2049_c.2050del, c.7156-2A>G and c,1303C>T. These mutations produce an out-of-frame transcript that will be degraded by nonsense-mediated decay. Therefore, we think these changes are pathogenic ones.