Identification of (Ala98Val) and (Ile27Leu) Mutation in exon 1 of HNF1-α (MODY 3) And their Association with early-onset Diabetes in Sudanese Families

Abstract

Maturity onset diabetes of the young (Mody3) is a monogenic form of diabetes. Gene defects in the Hepatocyte Nuclear Factor -1 alpha (HNF1-α) causes MODY3. HNF1-α gene located in the chromosome (12q24.2).A prevalent amino acid polymorphism at Ala98Val,I27L inexon-1 of HNF1-α was shown to be associated with diabetes in different study in many countries Asian, there for the aim of the study to see the classification and percentage of the patients have MODY have mutations of HNF1-α (MODY 3) gene with references to exon 1 by amplifying and sequenceing the coding regions of the gene in the etiology of diabetes in a sample of Sudanese families in Khartoum State. This was a case control study, conducted at the period from October 2013 to August 2017, in Khartoum state. Blood samples were collected from 80 diabetic patients, and 80 non-diabetic controls. Age, sex, weight, and height were recorded. Biochemical profiles of blood glucose level, HbA1c and C-peptide were estimated. From extracted DNA, exon 1 in HNF1-α gene was amplified using Polymerase Chain Reaction (PCR). Restriction Fragment Length Polymorphism (RFLP) was carried out to identify the occurrence of A98V mutation. Then DNA sequencing was done to detect other mutation in coding region of exon 1. HNF1-α A98V mutation was investigated in all patients and controls by PCR- RFLP, this mutation was not detected in all participants, and the result was confirmed by using DNA sequencing, while other two SNPs missense(I27L) and synonymous (L17L) were also detected. The study showed the occurrence of two mutations I27L &L17L, in one Sudanese diabetic family while L17L mutation was detected alone in 4 different Sudanese families