Mutations in the alpha-2 subunits of the Laminin (LAMA2) gene result in the deficiency of a key structural skeletal muscle protein known as merosin and cause an autosomal recessive congenital muscular dystrophy (CMD) subtype known as the laminin a2-related muscular dystrophies (LAMA2-RD). The gene discussed is LAMB2; the disease is congenital muscular dystrophy.