CRYABA gene on chromosome 11q22.3-q23.1 that encodes alpha crystallin B, a protein induced by heat shock that belongs to the small heat shock protein (sHSP, or HSP20) family. Alpha crystallins have features of molecular chaperones, but do not renature and release proteins like true chaperones.
Defects in CRYAB cause:
• Cataract posterior polar type 2;
• Myofibrillar myopathy fatal infantile hypertonic alpha-B crystallin-related;
• Myofibrillar myopathy type 2.