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

AIMS: Neonatal 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 6months versus those diagnosed between 6 and 12months of age. METHODS: We reviewed medical records of children with diabetes diagnosed before 12months of age. Genetic testing was performed in all cases. RESULTS: 12 patients were diagnosed with diabetes before 6months of age (PNDM=6; TNDM=6), and 11 patients between 6 and 12months (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 12months, 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. CONCLUSIONS: Investigating the underlying genetic basis of diabetes in children with onset before 1year is useful for choosing the most efficient treatment, the basis of Personalized Medicine.

Increased plasma incretin concentrations identifies a subset of patients with persistent congenital hyperinsulinism without KATP channel gene defects.

Congenital hyperinsulinism causes profound hypoglycemia, which may persist or resolve spontaneously. Among 13 children with congenital hyperinsulinism, elevated incretin hormone concentrations were detected in 2 with atypical, persistent disease. We suggest that incretin biomarkers may identify these patients, and that elevated hormone levels may contribute to their pathophysiology.

Clinical and molecular basis of transient neonatal diabetes mellitus in Brazilian children.

We report a series of patients with transient neonatal diabetes mellitus (TNDM). Paternal uniparental isodisomy of chromosome 6 and heterozygous KCNJ11 and ABC88 mutation were the mutations found. This first reported series of Brazilian patients expands the geographical data on TNDM contributing to better understanding of its pathophysiology.