Comprehensive Evaluation of Sibling Cases with Type 1 Diabetes.

Objective: Type 1 diabetes mellitus (T1DM) is a polygenic disease influenced by genetic, environmental, immunological factors.There are few studies regarding siblings with T1DM.We aimed to evaluate the presentation, diagnosis, follow-up, sociodemographic characteristics of sibling T1DM cases. Material and Methods: We retrospectively reviewed characteristics of sibling cases followed with T1DM between January 2005 and May 2017. Results: The prevalence of T1DM sibling diabetes in our clinic was 5.9%.We included 17 siblings (a total of 34 cases) who had diagnosis and follow-up data. One of the siblings was a twin.There were no statistically significant differences between the ages at diagnosis, presenting symptoms, duration of symptoms before diagnosis, glucose/C-peptide values at diagnosis, average HbA1c values in the first five years of follow-up, or hospitalization rates in the first five-years post-diagnosis between the first and second diagnosed siblings.Despite having a child diagnosed with T1DM, 23.6% of families had a second child diagnosed with diabetic ketoacidosis.Variations in antibody positivity were observed among siblings, there were no similarities between celiac disease, Hashimoto's thyroiditis.Vitamin D levels were significantly lower in siblings diagnosed secondarily. Conclusion: Our study is significant for being conducted at a reference center with a high number of diabetes patients under follow-up, for filling a gap in the literature with a detailed evaluation of sibling cases with T1DM.It serves as a comprehensive pilot study examining the manner, order of diagnosis, clinical, laboratory, and follow-up data of siblings with diabetes.There is a need for prospective studies with a larger number of sibling cases to further explore this topic. [ABSTRACT FROM AUTHOR]