Evaluation of HLA-G 14bp Ins/Del and +3142 C/G Polymorphisms in Type 1 Diabetes among South Indian Population

Nagarajan Gunavathy; Arthur Asirvatham; Ayyappan Chitra; Mariakuttikan Jayalakshmi

doi:10.4103/ijem.ijem_7_22

Evaluation of HLA-G 14bp Ins/Del and +3142 C/G Polymorphisms in Type 1 Diabetes among South Indian Population

Indian J Endocrinol Metab. 2023 May-Jun;27(3):223-229. doi: 10.4103/ijem.ijem_7_22. Epub 2023 Jun 26.

Authors

Nagarajan Gunavathy¹, Arthur Asirvatham², Ayyappan Chitra³, Mariakuttikan Jayalakshmi¹

Affiliations

¹ Department of Immunology, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India.
² Department of Diabetology, Government Rajaji Hospital, Madurai, Tamil Nadu, India.
³ Institute of Child Health and Research Centre, Government Rajaji Hospital, Madurai, Tamil Nadu, India.

Abstract

Background: Type 1 diabetes (T1D) is a multifactorial autoimmune disease, involving strong genetic components with familial predisposition. Human leukocyte antigen-G (HLA-G) is a non-classical HLA-class I molecule having several immunomodulatory functions. Polymorphisms in HLA-G are associated with several autoimmune diseases including T1D. This study aims to evaluate the association of HLA-G 14bp Ins/Del and +3142 C/G polymorphisms with T1D among the South Indian population.

Methods: The study was performed in a cohort of 123 T1D patients along with their 51 siblings and 126 parents. The association and linkage of HLA-G 14bp Ins/Del and +3142 C/G polymorphisms with T1D were analysed, and transmission disequilibrium test (TDT) was performed.

Results: Significantly increased frequencies of HLA-G 14bp Del/Del genotype (OR = 2.16, p_c = 0.0302) and Del allele (OR = 1.71, p_c = 0.0398) were observed in female patients compared to parents. Higher frequencies of DelDel/GG combined genotype (OR = 4.45, p_c = 0.0049) and Del/G haplotype (OR = 2.91, p_c = 0.0277) were observed in female patients compared to parents. TDT also revealed over-transmission of Del/G haplotype (25T vs 7UT; P = 0.0015) and a strong linkage disequilibrium between the studied polymorphisms.

Conclusion: This familial study shows the association of HLA-G 3'UTR 14bp Ins/Del polymorphism with the risk of T1D among the South Indian population, especially in females.

Keywords: HLA-G; South India; polymorphism; type 1 diabetes.