Author/Authors :
KHALIL, MONA S. Cairo University - Faculty of Medicine - Department of Clinical Chemical Pathology, Egypt , EL-MOUGY, FATMA Cairo University - Faculty of Medicine - Department of Clinical Chemical Pathology, Egypt , KHALAFALLA, OSSAMA Cairo University - Faculty of Medicine - Department of Clinical Chemical Pathology, Egypt , MANDOUR, IMAN Cairo University - Faculty of Medicine - Department of Clinical Chemical Pathology, Egypt , EL-GAYAR, DINA Cairo University - Faculty of Medicine - Department of Clinical Chemical Pathology, Egypt , GAMAL EL-DIN, HALA A. Cairo University - Faculty of Medicine - Department of General Medicine, Egypt
Abstract :
Over the years several studies have examined the inheritance of diabetes mellitus (DM) and have reported an excess of maternally inherited diabetes. Many DNA mutations are incriminated in the disease production, one of which is the A to G mutation at position 3243 of the mt DNA within the tRNA leucine gene. The aim of this work is to screen a group of diabetic patients for mt DNA mutation at bp 3243 and its correlation with autoantibodies; namely; glutamic acid decarboxylase antibodies (GAD ab), antibodies to tyrosine phosphatase- like proteins (anti-IA-2) and anti-insulin antibodies (IAAs) and to correlate these results with the degree of glycaemic control. The study was conducted on 93 cases with type I diabetic patients (group I), and 93 cases with type II diabetic patients (group II). Fasting, post-prandial blood sugar, glycosylated hemoglobin, anti-GAD abs, anti-IA-2 abs and anti-insulin abs were assayed for each case. Mitochondrial DNA analysis and detection of the mutation at bp 3243 was done using a PCRRFLR The mt DNA mutation at bp 3243; was not detected in any case; and consequently, no statistical correlations or comparisons could be presented. On comparing both types of DM, a significantly higher anti-IA-2 ab in type II DM patients as compared to type I DM (p 0.05) was found. The prevalence of positive anti-GAD ab was higher in type I DM patients (90.3%) than those of type II (40.9%) (p 0.01), and the prevalence of positive anti-IA-2 ab which was higher in the type II DM patients (31.2%) than those of type I DM (20.5%) (p 0.05). The prevalence of negative autoantibodies was higher in type II DM patients (38%) than those of type I (4%) (p 0.01). Conclusion: Antibody combinations were found to be the means for improving the risk assessment of DM. The result of the mt DNA analysis performed showed that the mt DNA mutation at bp 3243 was not detected; however it might be detected upon using a larger properly selected population.
