Patched 2 gene is mapped on chromosome 1p34.1 that contains 23 exons spanning at about 15kb genomic DNA which encodes 1,203 amino acids putative transmembrane and has two terminal cytoplasmic domains to formed a membrane complex that serves as a receptor for Sonic hedgehog (SHH). It has two isoforms in which one shows an eight aa extension of the C-terminus while the second demonstrates four aa substitutions for the C-terminal.
Patched 2 chiefly expressed in testis and skin which localized in cellular membranes. It mediates the Dessert Hedgehog in testicular development affecting in the tissues that could act as suppressor in germ cell tumors. It is a novel patched gene that undergo alternative splicing and up-regulated in basal cell carcinomas.
Patched 2 gene mutation is implicated in nevoid basal cell carcinoma syndrome as well as in sporadic basal cell carcinomas and medulloblastomas. It is also implicated in neurofibromas, pituitary tumors, menigiomas and tissue development detected in thymus, ovary, prostate and bone. Alteration of this gene plays a major role in BCC development that is responsible for hereditary BCC in Gorlin’s syndrome.
Gene name: PTCH2
Protein name: Protein patched homolog 2(PTC2)