The CTLA4 -819 C/T Dimorphism Is Associated with Type 1 Diabetes in Egyptian Children

Abstract

Background: We investigated whether the C-819T SNP of the CTLA4 gene is associated with Type 1 diabetes (T1D) for the Egyptian population, a multi-ethnic group.  We determined if expression of the C-819T SNP correlated with onset of T1D for Egyptian children and the prevalence of this polymorphism with respect to gender.
Methods: The association of the C-819T SNP in intron 1 of the CTLA-4 gene with T1D was investigated in 396 Egyptian pa­tients ≤ 14 years old and 396 control subjects >24 years old, with a similar ratio of males to females in both groups.  The di­agnosis of T1D was made based on ketoacidosis or ketosis with severe symptoms of acute onset at presentation and con­tinuous dependence on insulin. Controls were negative for anti-GAD antibodies and were greater than 24 years of age.  Geno­typ­ing was performed using single strand conformation polymorphism (SSCP), temperature gradient gel elec­trophoresis (TGGE), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and reverse dot blot (RDB).
Results: The results demonstrated an association of the C-819T SNP in the CTLA-4 gene with T1D patients (P= 0.0096).  This association was more pronounced in children ≤5 years of age (P= 0.0178) than in children 6-14 years of age (P= 0.0437).  More­over, this association was stratified by gender and age to female patients with age at onset 0-5 years old (P= 0.0186) more than male patient with the age at onset 0-5 years old (P= 0.3120).
Conclusion: The results support an association of the C-819T SNP in the CTLA-4 gene with Egyptian children, specifi­cally, females of onset age 0-5 years old.