1. ¹Research Unit for Photodermatology, Department of Dermatology, Medical University of Graz, Graz, Austria
2. ²Institute for Medical Informatics, Statistics, and Documentation, Medical University of Graz, Graz, Austria
3. ³Department of Dermatology, Medical University of Graz, Graz, Austria

Correspondence: Dr Peter Wolf, Department of Dermatology, Medical University of Graz, Auenbrugger Platz 8, A-8036 Graz, Austria. E-mail: peter.wolf@meduni-graz.at

Received 2 February 2007; Revised 2 April 2007; Accepted 20 April 2007; Published online 28 June 2007.

Abstract

Basal cell carcinoma (BCC) shows a wide interpatient variation in lesion accrual. To determine whether certain tumorigenic fingerprints and potentially predisposing patched (PTCH) tumor suppressor single-nucleotide polymorphisms (SNPs) are distributed differently among sporadic BCC patients, we compared the PTCH mutation spectra in early-onset BCC (first lesion at age <35 years), regular BCC (first lesion at age 35 years and <10 lesions), and multiple BCC (10 lesions). The PTCH gene was mutated in 29 of 60 cases (48%). Most of the PTCH mutations bore the UV fingerprint (i.e., C T or tandem CC TT transitions at dipyrimidine sites). However, neither the proportion nor the spectra of exonic PTCH mutations differed significantly among the three groups. A large number of SNPs (IVS10+99C/T, IVS11-51G/C, 1665T/C, 1686C/T, IVS15+9G/C, IVS16-80G/C, IVS17+21G/A, and 3944C/T or its combinations) were also detected, but again their incidence did not differ significantly among the groups. Interestingly, expression of the IVS16-80G/C and the IVS17+21G/A genotype did not achieve the Hardy–Weinberg equilibrium in patients with regular and/or early-onset BCC. These data suggest that a (UV-) mutated PTCH gene is important for sporadic BCC formation independent of clinical phenotype and that the IVS16-80G/C and/or IVS17+21G/A SNP site might be important for tumorigenesis in certain BCC patients.