What causes integrin-alpha7 deficiency congenital muscular dystrophy (CMD)?

Updated: Jul 03, 2019
  • Author: Emad R Noor, MBChB; Chief Editor: Amy Kao, MD  more...
  • Print
Answer

This is an autosomal recessive disorder caused by a mutation on chromosome 12 in the gene for integrin-α7.

Integrin-α7 is a member of the integrin family, which comprises transmembrane adhesion molecules that exist as heterodimers composed of one alpha and one beta chain.

Integrin-α7-β1 is the primary integrin in skeletal and cardiac muscle and skeletal myotubes.

It functions as a transmembrane link between laminin-α2 and the muscle membrane that is independent of the dystrophin-glycoprotein complex (see below). The complex bridges the inner cytoskeleton (F-actin) and the basal lamina. Mutations in laminin-α2, integrin α7, and O-glycosyltransferases that glycosylate alpha-dystroglycan all can cause CMD. Mutations in collagen, which binds α -dystroglycan through perlecan and other proteoglycans, can cause CMD. Mutations in dystrophin, the sarcoglycans, dysferlin, and caveolin-3 can also cause muscular dystrophies. [32]

It may play a role in myoblast migration and in the formation of myotendinous and neuromuscular junctions.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!