Study On The Relationship Between The Polymorphisms Of Muscle Glycogen Synthase Gene And Type 2 Diabetes Mellitus And Complicated Hypertension

Objectives Type 2 diabetes mellitus (T2DM) is a heterogeneous disease induced by interaction of genetic factors and environmental factors. Genetic factors play a important role in the pathogenesis of T2DM. The genetic factors of T2DM include insulin resistance and impaired functions of (3 cells in islets of langerhans. Glycogen synthase (GS) is in correlation with insulin resistance, and subsequently it's gene has become a major candidate gene for T2DM. It had been found that there are defects in synthesis and activation of GS in skeletal muscle of T2DM patients and their first degree relatives, so muscle glycogen synthase gene (GYS1) has become a hotspot of study in gene mutations. It had been reported that the Xba I polymorphism (A2 allele) of GYS1 intron 14 is associated with high risks of insulin resistance and T2DM in Finnish population. But with respect to other studies in France, Japan, Russia, Shanghai and Henan province of China, the A2 allele is not associated with T2DM. Furthermore, it had been reported that A2 allele is associated with hypertension. The aim of this study is to investigate the prevalence of the Xba I polymorphism of GYS1 intron 14 and to find out the correlation between A2 allele and T2DM and complicated hypertension in the Han nationality population in Tianjin of China.Methods1. To collect the blood samples of T2DM subjects (including patientswith hypertension) and normal control subjects.2. To extract and to purify the genomic DNA from the collected bloodsamples.3. Using PCR-RFLP technique, the Xba I polymorphism site of GYS1intron 14 was screened in 334 T2DM subjects (including 188 patients with hypertension) and 116 normal controls.4. To sequence the polymorphic gene found by RFLP technique.5. To analyse the clinical data.Results No A2 allele was found in 334 T2DM subjects (including 188 patients with hypertension). Only one A2 allele was found in 116 normal controls. In the controls, the A2 allele frequency is 0.0043, the A1/A2 genotype frequency is 0.0086, and these data are lower significantly than those in majority reports inland or abroad. The A2 allele frequencies are similar between T2DM patients and normal control subjects. Also the A2 allele frequencies do not differ significantly between T2DM patients with hypertension and patients without hypertension or healthy controls.Conclusions The Xba I polymorphism of GYS1 intron 14 is not associated with T2DM and complicated hypertension in Han nationality population in Tianjin of China. This polymorphism may be a genetic marker of T2DM and hypertension in only parts of races or populations.