Two novel STK11 mutations in three Chinese families with Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is an autosomal dominantly inherited disease. STK11/LKB1 gene germline mutations have been identified as responsible for PJS. In our study, we investigated the molecular basis of PJS and evaluated correlation between the STK11 mutations and the Chinese population. METHODS: We collected three pedigrees of PJS and screened the 9 exons and their flanking intronic sequences of STK11/LKB1 gene in the probands and normal individuals in the families using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Sequencing of the STK11 gene in the probands of 3 families revealed two novel mutations (c180C-->G and c998-1002delGCAGC) in exon 1 and exon 8, respectively. The mutation of c180C-->G resulted in a premature termination codon. The other mutation, a deletion of five nucleotides (998-1002delGCAGC) in exon 8, predicted to generate a translational frameshift and a termination at codon 1070. CONCLUSIONS: The growing number of mutations in PJS pedigrees suggests the molecular basis of PJS. STK11 gene mutation can be detected in most patients with PJS.