Naevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is inherited in an autosomal dominant mode characterised by a combination of developmental anomalies and a predisposition to form tumours. Our aim was to search for patched homologue 1 (PTHC1) mutations in a Chinese family with NBCCS. Mutation analysis of PTCH1 was done of all 10 members of this family by amplified polymerase chain reaction and direct sequencing. Two novel PTCH1 mutations (3146A-->T, 1686C-->T) were identified in all five affected members. The mutation, 3146A-->T in exon 17, is predicted to lead to different PTCH protein translations. 1686C-->T mutation in exon 11 is a nonsense mutation. These mutations were not found in any unaffected members of this family or in 100 unrelated healthy Chinese people. Our findings suggest that the 3146A-->T mutation in the PTCH gene may be the cause of NBCCS by affecting the conformation and function of the PTCH protein.