Clinical and genetic features of Argentinian children with diabetes-onset before 12 months of age: Successful transfer from insulin to oral sulfonylurea

AimsNeonatal diabetes mellitus (NDM) is a rare monogenic disorder, reported to affect less than 2 cases per 100,000 infants. There are two types, permanent (PNDM) and transient (TNDM). We describe our clinical experience in determining and comparing the genetic basis of diabetes in children with onset before 6 months versus those diagnosed between 6 and 12 months of age.MethodsWe reviewed medical records of children with diabetes diagnosed before 12 months of age. Genetic testing was performed in all cases.Results12 patients were diagnosed with diabetes before 6 months of age (PNDM = 6; TNDM = 6), and 11 patients between 6 and 12 months (all with permanent diabetes). Among children with PNDM, we identified three different KCNJ11 mutations in 5 patients, and one novel ABCC8 mutation in a single patient. Among children with TNDM, we detected a KCNJ11 and ABCC8 mutation each in a single patient and methylation abnormalities at chromosome 6q24 in 4 patients.Among children with diabetes diagnosed between 6 and 12 months, 1 patient had an INS mutation and one patient was homozygous for an SLC19A2 mutation which confirmed a diagnosis of thiamine-responsive megaloblastic anaemia syndrome. Five of the patients with an ABCC8 or KCNJ11 mutation have successfully transferred from insulin to glibenclamide whist 1 child demonstrated a partial response to sulfonylurea treatment.ConclusionsInvestigating the underlying genetic basis of diabetes in children with onset before 1 year is useful for choosing the most efficient treatment, the basis of Personalized Medicine.