Correlation between human BDNF rs6265 gene polymorphism and type-2 diabetes and diabetic peripheral neuropathy

Abstract

Background & objective: Diabetes mellitus is quite common and globally prevalent condition affecting patients’ quality of life. Patients who have type 2 diabetes mellitus (T2DM), are more likely to get diabetic peripheral neuropathy (DPN), which may affect feet, legs, hand, and arm. A BDNF gene rs6265 polymorphism in humans results in the substitution of valine with methionine at codon 66 (Val66Met). We aimed to find the possible link between human BDNF rs6265 gene polymorphism and T2DM with and without peripheral neuropathy and compare it with healthy subjects in Kirkuk City, Iraq. Methodology: One hundred subjects were chosen to participate in this research, aged from 35 to 75 y and divided into three groups: 35 DPN, 35 T2DM patients, and 30 healthy controls were selected randomly for BDNF gene rs6265 SNP screening by using conventional PCR with specific sets of primers. Products of PCR for patients and control groups were run on the gel electrophoresis to detect the SNP rs6265 fragment. A nerve-conducting study was used to examine DPN. Results: The observed results demonstrated the presence of two types of alleles identified as genotypic variants (GG and GA) among all participants in this investigation. By applying the Hardy-Weinberg Equilibrium principle (HWE) for both patient and control groups, the results proved that there was a statistically significant variance (P < 0.05) in the genotypic frequencies between each of the groups that had been studied. The wild homozygous GG genotype in type 2 diabetic without neuropathy, with DPN, and healthy control group were 51.4%, 40% and 80% respectively. The heterozygous GA genotype were 48.6%, 60% and 20%, respectively in the three groups. Conclusion: The present study showed that the BDNF (Val66Met) rs6265 polymorphism is associated with type 2 diabetes mellitus and diabetic peripheral neuropathy in heterozygous allele G/A (Met/Met) and homozygous allele GG (Val/Val) genotype. Also, the current study found the absence of the mutant genotype AA, possibly due to the evidence that the distribution of the BDNF polymorphisms varies widely among different ethnic groups. Abbreviations: BDNF - Brain-derived neurotrophic factor; DPN - Diabetic peripheral neuropathy Keywords: Type2 diabetes mellitus; Diabetic peripheral neuropathy; Brain-Derived Neurotrophic Factor; BDNF rs6265 SNP; BDNF Val66Met polymorphism. Citation: Hamid R, Al-Wasiti E, Jabbar AM. Correlation between human BDNF rs6265 gene polymorphism and type-2 diabetes and diabetic peripheral neuropathy. Anaesth. pain intensive care 2024;28(4):752−756. DOI: 10.35975/apic.v28i4.2517 Received: March 08, 2024; Reviewed: April 20, 2024; Accepted: April 28, 2024