Lack of association of the WRN C1367T polymorphism with senile cataract in the Israeli population

Abstract

Purpose: Werner syndrome is an autosomal recessive disease of premature aging caused by a polymorphic C1367T mutation in the Werner (WRN) gene. Although there are differences between the pathobiology of normal aging and the phenotype of Werner syndrome, the clinical age-related changes are similar. The aim of the study was to investigate the incidence of the C1367T (rs1346044) polymorphism in patients with age-related cataract.

Methods: The study group consisted of 81 patients with senile cataract undergoing cataract extraction surgery. Data on age, sex, and medical history of microvascular disease and cancer were obtained from the medical files. Anterior lens capsule material was collected during surgery. DNA was extracted, amplified by polymerase chain reaction, and screened for the C1367T polymorphism in WRN using restriction enzymes followed by sequencing.

Results: There were 33 male and 48 female patients of mean age 74.3+/-9 years. Genotypic frequencies were 67% for TT and 33% for TC. None of the patients had the CC genotype. Ten patients had a history of myocardial infarct, 8 cerebrovascular accident, and 8 various tumors. The distribution of these morbidities was similar in the two genotype groups.

Conclusions: The distribution of the C1367T WRN polymorphism in patients with senile cataract is similar to that in the normal population. Cataract formation in the elderly is not linked to a WRN mutation.

Figure 1

DNA sequencing. CT, TT, and CC polymorphism is demonstrated, respectively. The later is for demonstration, not from the study population.

Figure 2

The C1367T polymorphism. Following the use of restriction enzymes, the gel shows: 1, DNA ladder; 2, PCR product well, demonstrating a 195 bp length sequence; 3, TT well, demonstrating two lengths of DNA of 158 bp and 37 bp; 4, CT well, demonstrating 4 DNA lengths of 158 bp, 93 bp, 65 bp, and 37 bp; 5, CC well, demonstrating 3 DNA lengths of 93 bp, 65 bp, and 37 bp (example taken as control).