Introduction: Neonatal Diabetes Mellitus (NDM) is a rare monogenic diabetes, with an incidence ranging from 1in 90000 to 500000 newborns in Europe. It is defined as persistent hyperglycemia occurring in first 6 months of life, due to an insulin deficiency.Based on the treatment duration, NDM is stratified as transient NDM (TNDM) and permanent NDM (PNDM).Clinical picture of NDM at diagnosis include intrauterine growth retardation (IUGR), hyperglycemia, glycosuria , polyuria, dehydration and respiratory distress.Insulin administration corrects metabolic disorders and provides weight catch.
Transitional and permanent forms have different genetic bases.NDM is linked in the majority of cases (70% ) to abnormalities in an imprinted region on chromosome 6q24, and in 30% to genetic mutations: KCNJ11, ABCC8, INS and HNF1β PNDM is genetically heterogeneous and several genes have been linked to this disorder. It may be isolated or associated to other syndromic entities. Its etiopathogenesis is increasingly elucidated.
Purpose: this work aims to study epidemiological, clinical, biochemical, genetic, therapeutic aspects and outcome of NDM
Methods: Descriptive Retrospective study from January 2006 to February 2015. We included all infants diagnosed with diabetes before 6 months of age, and followed at our department for diabetes mellitus.
Results: 13 infant with NDM were studied. Consanguinity was present in 54%, and a familial story of diabetes in 77%. 38% of these children had IUGR. Cardinal
symptoms were dehydration, vomiting, diarrhea, osmotic polyuria. 62% presented with diabetic ketoacidosis (DKA), and only 46% had a provisional diagnosis of diabetes or DKA at first physician contact. Peptide C levels were generally low, and all patients tested were negative for autoimmune markers of diabetes. No case of pancreatic agenesis was found in our study. Recessive genetic disorders were the commonest cause of NDM. Mutations of EIF2AK3 and INS were found to be responsible for 46% of NDM cases. Mutations in ABCC8 gene were found in only two cases (15%), which one is candidate for DEND syndrome. Transfer from insulin to oral sulfonylurea was started in index patient. Hypoglycemia and associated co-morbidities are the major problems in the majority of our patients.
Conclusion: in our study genetic etiology are different compared to Europeans and British patients, and it may due to the higher rate of consanguinity. However KATP mutations (ABCC8, KCNJ11) should be systematically screened, in raison of their impact on the management and prognosis of NDM