Diabetes Mellitus Under The Age Of One Year: Clinical Pattern, Etiological Factors And Possible Mutation In KCNJ11 Gene Encoding Of Adenosine Tri-Phosphate Sensitive Potassium Channel Gene ( Kir6.2) Among Egyptian Infants

Abstract

Background& aim: Infantile onset diabetes mellitus (IODM) is not uncommon metabolic disorder in children, with rising in the incidence in the last few years. This research is to study clinical pattern of infantile diabetes, etiological factors and possibility of being monogenic versus type 1 diabetes mellitus through laboratory and genetic study.

Patients& methods: A descriptive study includes 50 diabetic patients with disease onset under the age of one year. Detailed medical history was taken from patients' parents and complete clinical examination. All patient subjected to laboratory investigation include HbA1C, fating C peptide, islet cell AB and inulin autoantibody. Genetic testing  was done  for mutations in EIF2AK3, KCNJ11, ABCC8, INS, FOXP3, GATA4, GATA6, GCK, GLIS3, HNF1B, IER3IP1, PDX1, PTF1A, NEUROD1, NEUROG3, NKX2-2, RFX6, SLC2A2 for all patients diagnosed < 6m, and SLC19A2, STAT3, WFS1, ZFP57 using targeted next-generation sequencing (NGS) panel.  Sequence analysis of KCNJ11 and INS genes by Sanger sequencing were done for patients from 6-9m age at diagnosis of diabetes.

Results: The rate of DKA at time of presentation was 90%. Islet cell and insulin autoantibodies were negative in 36 (72%) patients and positive in 14 (28%) patients. Fasting C peptide was low in 74%. Genetic study could not detect genetic cause

Conclusion: Infantile onset diabetes mellitus (IODM) is uncommon but with rising incidence in the last few years. IODM diagnosis and management is challenging, late diagnosis due to lack of awareness among pediatrician that DM may occur at any age or due to lack of typical manifestations of DM (polyuria, polydipsia, weight loss)  is associated with high morbidities and mortalities.