Ethnic variation of IL‐4 intron 3 VNTR gene polymorphism; its association with type 2 diabetes mellitus and its complication (neuropathy) in Egyptian subjects

• Published in: American journal of medical genetics. Part B, Neuropsychiatric genetics Neuropsychiatric genetics, 2018-10, Vol.177 (7), p.635-640
• Main Authors: Ali, R., El‐Said, A., El‐Baz, H., Settin, A.
• Format: Article
• Language: English
• Subjects: Alleles; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Diabetic neuropathy; Gene frequency; Gene polymorphism; Genetics; Genotype & phenotype; Haplotypes; IL‐4 (VNTR) neuropathy; Polymorphism; Population genetics; Statistical analysis
• ISSN: 1552-4841; 1552-485X
• DOI: 10.1002/ajmg.b.32647

Type 2 diabetes mellitus (T2DM) has multigenetic and environmental interactive factors. Although diabetic neuropathies (DPN) are the most common, but at the same time, the least recognized and understood long‐term complication of diabetes. This study aimed to investigate the association of IL‐4 VNTR gene polymorphism with T2DM complicated with neuropathy in Egyptian subjects. This is a case control study including 102 T2DM Egyptian patients, plus 188 unrelated healthy individuals as controls. They were evaluated for variable number tandem repeat (VNTR); 70 base pair repeats located in the intron 3; of IL‐4 gene using the PCR technique. Homozygote frequency of the three‐repeat allele (A1/A1) genotype of IL‐4 VNTR was nearly equal among diabetic cases and controls (60.8% vs. 62.2%, respectively). Heterozygous frequency of (A1/A2) genotype was higher among controls compared to cases (33.5% vs. 19.6%, respectively) but not statistically significant. The (A2) allele had a significantly higher frequency in diabetic cases compared to controls (29.3% vs. 21.0%, respectively) while the (A1) allele had lower frequency but not significant one (70.7% vs. 79.0%, respectively). Comparing cases complicated with diabetic neuropathy vs. noncomplicated cases regarding their polymorphic IL‐4 (VNTR) genotypes revealed a nonsignificant lower frequency of (A1A1) genotype (57.1% vs. 65.1%, respectively, p = .57) with a higher combined (A2A2 + A1/A2) genotype frequency (42.9% vs. 34.9%, respectively). Only two haplotypes (A1) & (A2) of IL‐4 (VNTR) gene were recognized among Egyptian population; (A2) allele may influence in diabetes but not its complication (neuropathy) among Egyptian diabetic patients.