HLA-G Polymorphisms Are Associated with Non-segmental Vitiligo among Brazilians.

Veiga-Castelli Veiga-Castelli,Debortoli Debortoli,Massaro Massaro,Cardili Cardili,Silva Silva,Donadi Donadi,Pereira Pereira,Simões Simões,Marcorin Marcorin,Oliveira Oliveira,Fracasso Fracasso,Souza Souza,Castelli Castelli,Sabbagh Sabbagh,Mendes-Junior Mendes-Junior

doi:10.3390/biom9090463

Abstract

(1) Background: Vitiligo is characterized by white patches on the skin caused by loss of melanocyte activity or the absence of these cells. The available treatments minimize the symptoms by retarding the process of skin depigmentation or re-pigmenting the affected regions. New studies are required for a better comprehension of the mechanisms that trigger the disease and for the development of more efficient treatments. Studies have suggested an autoimmune feature for vitiligo, based on the occurrence of other autoimmune diseases in vitiligo patients and their relatives, and on the involvement of genes related to the immune response. (2) Methods: We evaluated, by massive parallel sequencing, polymorphisms of the HLA-G gene in vitiligo patients and control samples, to verify if variants of this gene could influence the susceptibility to vitiligo. (3) Results: We detected an association with non-segmental vitiligo regarding the haplotype Distal-010101a/G*01:01:01:01/UTR-1, adjusting for population stratification by using ancestry-informative markers (AIMs). (4) Conclusions: It remains unclear whether the HLA-G variants associated with vitiligo were detected because of the high linkage disequilibrium (LD) with HLA-A*02, or if the HLA-A variants previously reported as associated with vitiligo were detected because of the high LD with HLA-G*01:01:01:01/UTR-1, or if both genes jointly contribute to vitiligo susceptibility.

Highlights

Vitiligo is characterized by skin depigmentation due to lack of melanocyte function or loss of melanocytes in the advanced stage of the disease, affecting people from various ethnic backgrounds.Its prevalence is around 1% in the United States and in Europe, but ranges from less than 0.1%to greater than 8% worldwide [1]
In this study we aimed to evaluate polymorphisms and haplotypes of the HLA-G gene by generation sequencing (NGS), considering all regulatory segments and exons, in vitiligo patients and controls from a Brazilian population, to investigate whether variants of this gene could influence the susceptibility to vitiligo
European ancestry among Brazilian vitiligo patients when compared to controls

Summary

Introduction

Vitiligo is characterized by skin depigmentation due to lack of melanocyte function or loss of melanocytes in the advanced stage of the disease, affecting people from various ethnic backgrounds.Its prevalence is around 1% in the United States and in Europe, but ranges from less than 0.1%to greater than 8% worldwide [1]. Vitiligo is characterized by skin depigmentation due to lack of melanocyte function or loss of melanocytes in the advanced stage of the disease, affecting people from various ethnic backgrounds. Vitiligo can be classified into two main types, segmental and non-segmental. Segmental vitiligo is less common, affecting 5%–16% of the cases; it has a unilateral distribution, it tends to occur at a younger age, with 87% of the cases diagnosed before 30 years, and it presents a better prognostic, possibly resulting from a somatic mosaicism effect. Biomolecules 2019, 9, 463 vitiligo, the most common form, has symmetrical and bilateral distribution and can occur at any age [2]. Its cause has not been established yet, there is evidence of a major autoimmune component, including the occurrence of autoantibodies against melanin in the affected individuals [3]

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