arthrogryposis, distal, type 2B(redirected from Sheldon-Hall syndrome)
arthrogryposis, distal, type 2BAn inherited condition (OMIM:601680) characterised by multiple congenital contractures, vertical talus, ulnar deviation of hands, severe camptodactyly and distinctive facies: triangular shape, prominent nasolabial folds, small mouth and prominent chin.
Caused by defects of:
• MYH3, which encodes a heavy-chain myosin involved in cytokinesis, cell shape and specialised functions;
• TNNI2, which encodes troponin I type 2, a protein expressed in muscle and cartilage;
• TNNT3, which encodes type-3 troponin T, the tropomyosin-binding subunit of troponin; and
• TPM2, which encodes beta-tropomyosin, an actin filament binding protein primarily expressed in slow, type 1 muscle fibres.