A highly conserved family of genes (paired domain genes, paired box genes) encoding transcription factors that are important in pattern formation during development. Pax1 (Hup48) is involved in development of the vertebral column. Pax2 is important in nephrogenesis and is mutated in renal–coloboma syndrome, Pax3 (Hup2) is involved in neurogenesis and mutations lead to Waardenburg's syndrome. The differentiation of endoderm-derived endocrine pancreas is mediated through Pax4 and Pax6; mutations in Pax4 are associated with susceptibility to diabetes. Pax5 has a role in B-cell differentiation and in neural development and spermatogenesis. Pax6 has a role in oculogenesis, and mutations cause aniridia and various other eye-releated disorders. Pax7 is required for neural crest formation, Pax8 is essential for the formation of thyroxine-producing follicular cells and mutation can cause hypothyroidism. Splice variants of some of the PAX gene products are known and it is likely that each factor has multiple tissue-specific roles.
Subjects: Medicine and health