Association of elevated homocysteine levels and Methylenetetrahydrofolate reductase (MTHFR) 1298 A > C polymorphism with Vitiligo susceptibility in Gujarat

Abstract

Background: Several studies have reported hyperhomocysteinemia in vitiligo patients, suggesting the potential role of elevated homocysteine levels in precipitating vitiligo.

Objectives: We aimed to estimate homocysteine and vitamin B₁₂ levels, and to investigate the role of MTHFR 677 C > T and 1298 A > C polymorphisms in vitiligo susceptibility in Gujarat population.

Methods: Homocysteine and vitamin B₁₂ levels were estimated in plasma of 55 vitiligo patients and 60 controls by Electrochemiluminescence immunoassay (ECLIA). Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) techniques were used to genotype MTHFR 677 C > T and 1298 A > C polymorphisms in 520 vitiligo patients and 558 controls.

Results: Our results showed significantly elevated homocysteine levels (p = 0.0003) as well as significant decrease in vitamin B₁₂ levels (p = 0.0102) in vitiligo patients, as compared to controls. No significant difference in genotype and allele frequencies of MTHFR 677 C > T polymorphism was observed among patients and controls, however, the frequency of 'CC' genotype of MTHFR 1298 A > Cpolymorphism was significantly increased in patients as compared to controls (p = 0.0151). Analysis based on the type of vitiligo revealed a significant increase in 'C' allele of MTHFR 1298 A > C polymorphism in patients with generalized (p = 0.003) and active (p = 0.007) vitiligo as compared to controls. Both the polymorphisms of MTHFR were in low linkage disequilibrium (LD) and susceptible 'TC' haplotype was more frequently observed (p = 0.008) in vitiligo patients. Interestingly, elevated homocysteine levels were also positively correlated with MTHFR 1298 A > C polymorphism in vitiligo patients. Structure based in silico prediction revealed structural perturbations in MTHFR protein due to Ala222Val and Glu429Ala amino acid substitution.

Conclusions: The present findings suggest that MTHFR 1298 A > C polymorphism and, altered homocysteine and vitamin B₁₂ levels might play a vital role in the precipitation of vitiligo.

Keywords: Genetic polymorphisms; Homocysteine; MTHFR; Vitamin B(12); Vitiligo.