ABSTRACT
Aim: The work wasto study polymorphisms in the LEP gene in type 2 diabetics in Minia, Egypt and determined the relationship between the leptin and c-peptide levels in different genotypes and insulin resistance in obese patients. The study also has evaluated the role of leptin gene polymorphism in prediction of diabetes mellitus prognosis and its prevention. Study Design: Investigative. Place and Duration of Study: Samples were analyzed at Biochemistry Department, Faculty of Medicine- Minia University, Egypt, between August 2012 and April 2014. Methodology: This study was performed in 80 patients with type 2 diabetes mellitus (54 men and 26 women) and 15 normal controls (12 men and 3 women). In our thesis we measured HbAc, fasting blood glucose, leptin hormone and c-peptide. DNA extracted and the human leptin gene (for product 242 bp) was amplified by PCR, Restriction analysis of the PCR products was performed with restriction enzyme HhaI and genotyped at the restriction site located -2549 bp from the transcription initiation site of leptin gene. Presence of allele (C at -2549 bp) and absence of allele (A at the same position) were identified through the GCGC sequence. Results: Our study showed C-2549 A variant is associated with the fasting leptin levels, the results which are in agreement with previous studies. The polymorphism in leptin gene has an effect on the level of plasma leptin in different genotypes, and individuals with AA genotype have the lower plasma levels of leptin and also c-peptide than AC and CC variants. Conclusion: Our study reveals that both diabetic patients and their non-diabetic relatives have different basal leptin and c-peptide specific to different leptin genotypes. This suggests that the association between leptin and insulin in members of diabetic families may be controlled by inheritance.