Abstract:

Objective To detect mutations of STK11 gene in peripheral blood and hamartomatous gastrointestinal polypi of 2 pedigrees and 3 sporadic patients with PJS. Methods Blood samples were obtained from some members in the 2 pedigrees, 3 sporadic patients, and 100 normal human controls, and tissue samples from gastrointestinal polypi of 2 patients in pedigree 1 and 100 patients with non-PJS diseases. DNA was extracted from these samples and subjected to PCR for the amplification of 8 upstream exons and flanking sequences of STK11 gene. DNA sequencing was performed. Results There was a new heterozygous mutation, 2039 G→C, which leaded to the substitution of tryptophan by cysteine at codon 308, in exon 8 of STK11 gene in gastrointestinal polyp tissue, but not in peripheral blood, of the 2 patients in pedigree 1. A transition mutation （12703A→G） was detected in intron 2 of STK11 gene in peripheral blood, but not in gastrointestinal polyp tissue, from the 2 patients in pedigree 1. In peripheral blood from the patients of pedigree 2, a reported SNP （16215 G/C） was detected in intron 7 of STK11 gene. No mutation was detected in any of the 3 sporadic patients. Conclusion A new STK11 gene mutation, G2039C, is found in a Chinese PJS pedigree, which may be involved in the genetic basis of PJS.

Key words: 【Keywords】 Peutz-Jeghers syndrome(PJS), STK11 gene, Mutation