Analysis of Leptin receptor, Glucocorticoid receptor,B-3 Aderenergic receptor and Tumour Necrosis Factor-a Gene Polymorphism in Type 2 Diabetes Mellitus in Kelantan Malays.

• Main Authors: Isa, Nizam, Ismail, Abd. Aziz AI-Safi, Mohamed, Mafauzy
• Format: Article
• Language: English
• Published: Pusat Pengajian Sains Perubatan, Universiti Sains Malaysia 2003
• Subjects: R Medicine
• Online Access: http://eprints.usm.my/44904/1/GP...Analysis%20Of%20Laptin%20Receptor%20Glucocorticoid%20Receptor%2C%20B3-%20Aderenergic%20Receptor%20And%20Rumor%20Necrosis%20Factor-cx%20Gene%20Polymorphism%20In%20Type%202%20Diabetes%20Mellitus%20In%20Kel%20Malays...2003...-24%20pages.pdf; http://eprints.usm.my/44904/
• Institution: Universiti Sains Malaysia

Diabetes is a complex disease with both genetics and environmental component in the pathogenesis. Progress in the human genetic has allowed a better understanding in the search for either specific or multiple affliction of the candidate gene susceptible for the disease. Since the past 3 years studies showed that several genes including the Leptin receptor, f33-adrenergic receptor, Tumour necrosis factor alpha (Tnf-a.) and Glucocorticoid receptor have been linked and their polymorphism associated to diabetes. However, the prevalence involvement and polymorphic variations differ markedly among the ethnic groups. In this initial project the choice of these candidate genes markers were selected from the biological pathway likely to the development and the progression of the NIDDM. Future research will include other known and related gene susceptible to the disease. The potential role of identification of these variant not only contribute to better understanding of the pathogenesis of the disease but it also provide a research tool for the studies to assess the association of the multiple genetics markers with the disease. We expect to define the association of these genes polymorphism to the pathogenesis of diabetes in the local population. Research Methodology Subject and control 50 patients clinically confirm as diabetes and attending the Diabetes Clinics in the HUSM were selected. The clinical characteristics including sex, age, body mass index, blood pressure measurements and biochemical analysis of HbA 1 c and fasting blood sugar were analyzed. 50 controls are normal individual who do not have diabetes. A total 10 ml blood were collectedin the EDTA container from each patients and normal individual for DNA extraction and further genetic analysis. Genetic determination Genomic DNA was extracted from the above sample using standard non-phenol extraction procedure. The genomic DNA were amplified using specific primers and polymerase chain reaction (PCR) conditions for each specific gene of interest according to published works with modification. The Restriction Fragment Length Polymorphism (RFLP) was applied for mutation analysis. Both PCR and RFLP products were subjected to electrophoresis on either agarose or polyacrylamide gel for allele identifications. Statistical analysis The chi-square test was carried out for comparison of the genotype frequency and level of the variable between the genotype groups was compared using analysis of variance (ANOVA). P values of less than 0.05 were considered as statistically significant.Results From the whole sample studied, genotype frequency for mutant allele in these four genes are ranging from 8.0% to 29.2%. The highest genotype frequency for mutant allele is the Pentanucleotide Insertion/Deletion Polymorphism of the 3' -UTR of Leptin receptor gene (17.0%), followed by Trp64Arg polymorphism of the p3-adrenergic receptor gene (10.0%), followed by Asn363Ser polymorphism of the Glucocorticoid receptor gene (4.0%) and the lowest is G-308A polymorphism of the Tumour necrosis factor alpha (Tnf-a.) gene (3.0°Al). While in normal control samples, the result shows genotype frequency for mutant genes are 16.0% (Lepr), 7.0% (Tnf-a), 3.0% (GRL) and 2.0% (~3-AR). All genes are not associated with the incidence of type 2 diabetes in Kelantan Malay subjects (p <0.05).Conclusion We suggested that all genes are not likely to be the major predispose in the incidence of type 2 diabetes in Kelantan Malay population except for f33-adrenergic receptor gene. Future studies should be done to screen for other polymorphism in same genes and also in other genes which have been reported in other populations to have significant association with the pathogenesis of type 2 diabetes.