A feature of several developmental disorders in which there is premature closure of the epiphyses, particularly of terminal limb bones, so that fingers and toes are shorter than normal. Type A1 brachydactyly is caused by mutation in the Indian hedgehog gene, or mutation at a locus on chromosome 5. Type A2 is caused by mutation in bone morphogenetic protein (BMP) receptor B1 or in growth/differentiation factor-5. Type B1 is caused by mutation in the ROR2 gene which encodes a receptor tyrosine kinase (NTRKR2, 943 aa) that is also mutated in autosomal recessive Robinow's syndrome. Type C brachydactyly is caused by mutation in the growth/differentiation factor-5 gene, Types D and E by mutation in the homeobox D13 (HOXD13) gene. Other forms of brachydactyly are known, although their molecular basis is unclear.
Subjects: Medicine and Health.