Role of HOX genes in human development.

Hox genes specify developmental boundaries and determine cell fate during morphogenesis. Recently, two human syndromes, synpolydactyly and hand-foot-genital were shown to result from mutations in HOX genes. Both disorders affect digital arch structures and can involve genitourinary malformations. These studies confirm the critical role of these highly conserved transcription factors in the specification of growth and patterning of skeletal elements and axial soft tissues in humans.