A novel mutation of the WRN gene in a Chinese patient with Werner syndrome.

Werner syndrome (WS) is an autosomal recessive inherited disease characterized by features of premature ageing. It is caused by mutations of the WRN gene encoding a protein with both exonuclease and helicase activities. The aim of this study was to identify gene mutations in a Chinese patient with WS. A 31-year-old Chinese man with typical features of WS was diagnosed as having probable WS. We performed PCR to scan 33 exons of the WRN gene of the patient, six members of his family, and 50 unrelated controls. Automated DNA sequencing identified the mutation in the patient as 3250delG. The proband's parents, son, younger brother and paternal grandmother were heterozygous. We did not find this heterozygous mutation in the proband's maternal grandmother or in any of 50 normal controls. The novel mutation in the WRN gene is responsible for the pathogenesis of WS and genetic detection is a useful method to confirm the diagnosis.