Glutathione S-transferase M1 genotype and age-related cataracts. Lack of association in an Italian population.

PURPOSE To investigate possible associations between the gene number and allelic forms of glutathione S-transferase M1 (GSTM1) and the occurrence of nucleic and cortical age-related cataracts. METHODS Patients with cortical cataract, nuclear cataract, mixed and cortical cataract, and no cataract were sytematically selected from subjects evaluated in the Italian-American Study of the Natural History of Age-Related Cataract. The patients were typed for the A, B, and null alleles of GSTM1 using a variation of the amplification refractory mutation system. RESULTS Forty-nine percent of patients (50/102) with cortical cataracts, 45% (13/29) with nuclear cataracts, 51% (36/71) with mixed nuclear and cortical cataracts, and 50% of controls (49/98) were homozygous for the null GSTM1 allele. Twenty-five percent of patients (26/102) with cortical cataracts, 24% (7/29) with nuclear cataracts, 31% with mixed nuclear and cortical cataracts, and 27% of controls (26/98) displayed only the A allele for GSTM1. Twenty-four percent of patients (24/102) with cortical cataract, 24% (7/29) with nuclear cataracts, 14% (10/71) with mixed nuclear and cortical cataract, and 18% of controls showed only the B allele for GSTM1. Two percent of patients (2/102) with cortical cataracts, 7% (2/29) with nuclear cataracts, 4% (3/71) with mixed nuclear and cortical cataracts, and 5% of controls (5/98) showed both A and B alleles for GSTM1. CONCLUSIONS No associations between the GSTM1 alleles, including the null allele, and cataracts were detected in this study.