[5][6] PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis.

The PTCH1 gene product, is a transmembrane protein that suppresses the release of another protein called smoothened, and when sonic hedgehog binds PTCH1, smoothened is released and signals cell proliferation.

Alternative splicing results in multiple transcript variants encoding different isoforms.

Additional splice variants have been described, but their full length sequences and biological validity cannot be determined currently.

[8][9][10] Some of these patients present cleft lip and palate among the holoprosencephaly features, and missense variants in PTCH1 were also found in a sequencing screening of nonsyndromic cleft lip and palate patients.