OBJECTIVETo analyze the sequence of STK11 gene coding region in 20 patients with Peutz-Jeghers syndrome and identify the point mutations in STK11 gene associated with the occurrence of the disease.

METHODSBlood samples were collected from 20 inpatients with Peutz-Jeghers syndrome treated in our center between January 2009 and October 2010. The sequence of STK11 gene coding region was analyzed using PCR and DNA sequencing and compared with the normal sequence of STK11 gene.

RESULTSOf the 20 patients with Peutz-Jeghers syndrome, 14 showed STK11 gene mutations in the coding region, including 1 patient having two mutations and 13 patients with a single mutation site. In one case, sequence analysis of the STK11 gene identified a novel type of STK11 germline mutation, in which the cytosine (C)460 was substituted by guanine (G) in exon 3 to result in a new amino acid at codon 154. Four patients from 2 families were found to have a common mutation. The remaining 6 patients were not found to have mutations in STK11 gene coding region.

CONCLUSIONMutations of STK11 gene is a major cause of Peutz-Jeghers syndrome. The missense mutation of 460 C→G in exon 3 of STK11 gene is a novel mutation associated with Peutz-Jeghers syndrome.