Background.  Vitiligo is an acquired idiopathic and polygenic disorder with progressive depigmentation of circumscribed patches. Its exact pathogenesis is unknown. The CD4 gene plays an important role in the cell-mediated immune response and its association with type 1 diabetes mellitus, which is an autoimmune disease, has been previously reported.

Methods.  Based on the assumption that autoimmunity is also involved in vitiligo, the CD4 gene was selected for study using a candidate gene approach. The pyrimidine-rich pentanucleotide repeat length polymorphism located in the promoter of the gene was studied. We screened 144 unrelated Iranian patients with vitiligo and 144 healthy matched controls by PCR.

Results.  The CD4*A4 allele has a susceptibility association with the development of vitiligo in the Iranian population (OR = 1.68, 95% CI 1.18–2.42; P < 0.01, Pc = 0.02). When we compared CD4*A4-containing genotypes in the case and control groups, even more significant positive association was identified (OR = 2.02, 95% CI 1.26–3.22; P < 0.01 and Pc < 0.01). The CD4 gene polymorphism has a modest association with the development of vitiligo in Iranian patients.