GTR Home > Conditions/Phenotypes > Basal cell carcinoma, multiple


Cutaneous basal cell carcinoma (BCC) is the most common cancer among people of European ancestry (Stacey et al., 2009). The primary environmental risk factor for BCC is sun exposure, but genetics also has a substantial role. Some of the sequence variants that confer susceptibility seem to operate through their association with fair-pigmentation traits common among Europeans, resulting in reduced protection from the damaging effects of ultraviolet (UV) radiation. Other sequence variants have no obvious role in pigmentation or UV susceptibility but instead seem to operate in the contexts of growth and differentiation of the basal layers of the skin (Stacey et al., 2008; Epstein, 2008; Gudbjartsson et al., 2008; Rafnar et al., 2009). See ASIP (600201), TYR (606933), and SHEP5 (227240) for examples of basal cell carcinoma associated with fair skin or sensitivity to sun. Basal cell carcinoma occurs as a feature of multiple syndromes, including basal cell nevus syndrome (BCNS; 109400), Bazex syndrome (301845), Rombo syndrome (180730), Brooke-Spiegler syndrome (605041), Muir-Torre syndrome (158320), and xeroderma pigmentosum (see 278700). Abnormalities in the Hedgehog signaling pathway are found in basal cell carcinomas; see SHH (600725) and SMOH (601500). [from OMIM]

Genes See tests for all associated and related genes

  • Also known as: BCNS, NBCCS, PTC, PTC1, PTCH, PTCH1
    Summary: patched 1

  • Also known as: PTC2, PTCH2
    Summary: patched 2

  • Also known as: CM-AVM, CMAVM, GAP, PKWS, RASA, RASGAP, p120, p120GAP, p120RASGAP, RASA1
    Summary: RAS p21 protein activator 1

  • Also known as: CRJS, FZD11, Gx, SMOH, SMO
    Summary: smoothened, frizzled class receptor

Clinical features


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