Identification of the Gene Involved in MMD3
Mutations in other genes besides dysferlin can cause a form of distal myopathy whose symptoms are almost identical to those caused by dysferlin deficiency. This project aims to identify the gene which has been mapped to a specific locus in the human genome (called the MMD3 locus) in families with a non-dysferlin form of Miyoshi Myopathy. Because of the very similar clinical presentation, it is likely that the MMD3 protein may be involved in a common pathway which dysferlin, which will help to elucidate the pathological mechanisms in both diseases.
Outcome: Identified Anoctamin-5 (ANO5) as the MMD3 gene. Like dysferlin, this gene is responsible for both a distal myopathy (MMD3) and a form of Limb-Girdle Muscular Dystrophy (LGMD2L). The protein it encodes is thought to be a calcium-activated chloride ion channel.