The association between PTPN22 C1858T gene polymorphism and type 1 diabetes mellitus: an Indonesian study

BACKGROUND: Type 1 diabetes mellitus (T1DM) is disease caused by the destruction of β pancreatic cells. The activation of T-lymphocyte and proliferation inhibitor are induced by protein tyrosine phosphatase non-receptor type 22 (PTPN22). However, the link between PTPN22 C1858T gene polymorphism and T1DM is still controversy. This study aimed to analyse the C1858T gene polymorphism in Indonesian children with T1DM. MATERIALS AND METHODS: This case-control study was conducted from March 2021 to May 2022 in the Endocrinology Outpatient Clinic at Dr. Soetomo Hospital and Tropical Disease Center Universitas Airlangga. Patients with controlled T1DM during the study period were included. The PTPN22 analysis used polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: Sixty-two children voluntarily participated in this study, and were equally divided into the T1DM and control groups. Most of the patients (94%, 58/62) are Javanese. This study revealed a more frequent CC genotype (9.4%) and allele-C (54.6%) polymorphism in the T1DM group, while more frequent CT genotype (100%) and allele-T (50%) polymorphism were in the control group. The C- and T-allele frequency was 54.6% and 45.4% in the T1DM group, respectively. The T1DM and control groups did not significantly differ (p= .2381). CONCLUSIONS: PTPN22 homozygous genotype-CC and allele-C polymorphisms are more frequent in patients with T1DM. However, the PTPN22 KEY MESSAGES: 1. The PTPN22 C1858T gene polymorphism does not significantly affect the susceptibility of T1DM in Indonesian children. 2. PTPN22 homozygous genotype-CC polymorphism was more observed in the T1DM group; thus, this genotype may play as a risk factor for T1DM children in the Indonesian population.