An investigation into the association between HLA-G 14 bp insertion/deletion polymorphism and multiple sclerosis susceptibility

Human Leukocyte Antigen G (HLA-G) gene polymorphism and expression rate have recently been suggested to have a potential role in susceptibility to Multiple Sclerosis (MS), a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system with unknown etiology. The aim of this study was to investigate the association of the frequency of HLA-G gene 14 by insertion/deletion polymorphism and its plasma level with MS susceptibility. In this study, the HLA-G gene from 212 patients and 210 healthy individuals was amplified using real time PCR and screened for the 14 bp insertion/deletion polymorphism. In addition, HLA-G plasma levels of the patients were measured and compared to normal controls by ELISA method. Our results revealed that 14 bp insertion in HLA-G could result in lower plasma HLA-G level of the subjects, regardless of their health status and vice versa. Additionally, significant correlation of HLA-G genotype and its plasma level with MS susceptibility was observed. In conclusion, not only HLA-G 14 bp insertion/deletion polymorphism could be associated with expression rate of the HLA-G gene and its plasma level, but also could be considered as a risk factor for susceptibility to MS in our study population. (C) 2015 Elsevier B.V. All rights reserved.