RESUMO
Objective To analyze mutations in the PTCH1 gene in a pedigree with nevoid basal cell carcinoma syndrome (NBCCS).Methods Blood samples were collected from a 58-year-old male proband with NBCCS (Ⅱ 5),his brothers (Ⅱ 1 and Ⅱ 3) and son (Ⅲ4),and 50 unrelated healthy human controls.DNA was extracted from these blood samples.PCR and direct DNA sequencing were performed to determine mutation sites in the PTCH1 gene.According to the mutation sites,allele-specific oligonucleotide primers were designed and used to confirm the pathogenic mutations in this pedigree through PCR.Results A nonsense mutation (c.2137C),which leads to the substitution of CAG by TAG with the generation of a premature termination codon (Q714X),was identified in exon 14 in one allele of the PTCH1 gene in the proband and his son,but in none of the healthy human controls.Conclusion The nonsense mutation (c.2137C ＞ T) in the PTCH1 gene may be a specific mutation causing the clinical symptoms in the patient with NBCCS.