CTLA-4 A49G GENE POLYMORPHISM IS NOT ASSOCIATED WITH VITILIGO IN SOUTH INDIAN POPULATION

BACKGROUND: Vitiligo or leukoderma is a chronic skin condition that causes loss of pigment due to destruction of melanocytes, resulting in irregular pale patches of skin. Vitiligo is a polygenic disease and is associated with autoimmunity with an unknown etiology. AIMS: One of the candidate genes which has a strong association with several autoimmune diseases is CTLA-4 gene located in chromosome 2q33 region. We investigated the possible association between CTLA-4 gene polymorphism in exon 1 (A49G) and vitiligo in patients from South India and compared the distribution of this polymorphism to matched control groups. PATIENTS AND METHODS: The polymorphism was detected by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method in 175 patients and 180 normal, age/ethnicity matched individuals. Consistency of genotype frequencies with the Hardy-Weinberg equilibrium was tested using a χ(2) test. RESULTS: There was no significant difference between the genotype (P = 0.93) and allele (P = 0.615) frequencies of CTLA-4 A49G polymorphism in patients and normal healthy individuals. However there was significant association of the CTLA-4 genotype (P = 0.02) and allelic frequency (P = 0.008) between the segmental and non-segmental sub groups within vitiligo. CONCLUSION: Our results indicate that there is no association between CTLA-4 A49G gene polymorphism and vitiligo in southern Indian population.