ESPE Abstracts

Objective: Lifetime risk of having Type 1 Diabetes Mellitus [T1DM] increases when having a blood relative with T1DM. A Finish study reports 12.2% and 11.9% of T1DMs having a first degree relative [FDR] and second degree relative [SDR] with T1DM[1]. Data from India regarding proportion of children with T1DM FDR/SDR is non-existent. Objective is to find out the same.

Methods: We examined the electronic database of 902 T1DM patients visiting our pediatric endocrine clinic between March 2014 to October 2022 to find the history of affected FDR and SDR with T1DM. We also interviewed the cases and affected relatives for other autoimmune disorders.

Results: Out of 902 newly diagnosed index cases, 20 [2.2%] had one FDR and 2 [0.23%] had 2 relatives with T1DM [both parents]. Nine [1%] cases had SDR with T1DM. At diagnosis, the index cases were between 11 months and 12 years of age (median 4 years); and FDRs were between 2-35 years [median 20years]. Among the 22 FDRs, 14 [63%] were parents [7 mothers] and 8 were siblings. Among the sibling FDRs, 6 were brother-sister pairs and 2 were brother-brother pairs. Autoimmune thyroid was present in 2 index and 2 FDRs [unrelated to their index]. None of the 20 FDRs had other autoimmune diseases [celiac disease, vitiligo, alopecia or hypoparathyroid]. There were 2 pairs of T1DM married couples, and both have T1DM children [Onset at one year].

Conclusion: This is the first reported data on T1DM in the FDR/SDR of index T1DMs. Indian T1DMs have much less prevalence than the western literature. Index cases had earlier onset than the relatives. Parent-sibling were commoner, without any gender predilection. [1] Parkkola A, Härkönen T, Ryhänen SJ, Ilonen J, Knip M; Finnish Pediatric Diabetes Register. Extended family history of type 1 diabetes and phenotype and genotype of newly diagnosed children. Diabetes Care. 2013;36(2):348-354.