Study of DNA Methylation in Children and Adolescents With Type 1 Diabetes Mellitus

Type 1 Diabetes Mellitus (T1DM) is a well-studied autoimmune disease resulting in insulin deficiency due to selective β-cell loss. Environmental and genetics factors seem to have a complex interplay in genetically susceptible individuals leading to T1DM development.

Epigenetics is a new field of biology studying the inherited changes in deoxyribonucleic acid (DNA) expression which cannot be attributed to DNA sequence alteration via DNA methylation, histone modification, and micro-RNAs acting as post-transcriptional regulators.

The methylation of cytosine - guanosine dinucleotides (CpGs), located at the promoter region of the genes, play a vital role in transcription and gene expression and is catalyzed at the 5' cytosine position via enzymes called DNA methyltransferases (DNMTs).

A limited number of studies regarding epigenetics in T1DM paediatric patients have been published so far. The purpose of the present study is to investigate the CpG islet methylation pattern in the promoter regions of specific susceptibility genes such as Protein tyrosine phosphatase, non-receptor type 22 (PTPN-22), Insulin (INS) and Human leukocyte antigen G (HLA-G) genes, extracted from White Blood Cells (WBCs) from T1DM and healthy controls children and adolescents .

Twenty patients and twenty age and gender matched controls were recruited. A detailed personal, family, gestational/perinatal history was obtained and a thorough physical examination was performed in all study participants. Both groups and their first grade relatives had no history of other autoimmune diseases.