Background: Neonatal diabetes mellitus (NDM) is a form monogenic diabetes diagnosed under 6 month of age.
Objective and hypotheses: To describe the clinical and molecular features of NDM patients in a Turkish cohort.
Method: Fifteen patients (13M, 2F) with diabetes onset before 6 months of age were included in the study. Clinical and molecular data were evaluated retrospectively.
Results: Mean age at diagnosis was 2.4±1.5 months (median 2, range 0.56 m). Gestational ages were between 35 and 40 weeks. Birth weight (BW) was between 1400 and 3680 g and BW-SDS −1.7±1.7 (median −1.1; range −5.0 to 0.6). Small for gestational age (SGA, BW <−2 SD) ratio was 40%. Consanguinity ratio was 66.7%. Mean serum glucose level at diagnosis was 29.4±8.9 mmol/l. Mutations are given in Table 1. In two siblings with ABCC8 mutations (p.E382K mutation), insulin therapy was switched to glibenclamide at the age of 15 and 11 years. They have been on sulphonylurea (SU) monotherapy for 9 years, recent HbA1c values were 6.5%. The third patient with ABCC8 mutation (p.R826W) was planned to transfer SU. The two patients with PTF1A mutation had exocrine pancreatic deficiency due to pancreatic hypoplasia. One patient with unknown genetic etiology was SGA and had also exocrine pancreatic deficiency. Patient with SLC19A2 mutation has sensorineural deafness, megaloblastic anemia, AV block, still on thiamine and subcutaneous insulin therapy (0.8 U/kg per day) at the age of 7 years. Patients with mutations in INS, PTF1A and two patients with unknown genetic etiology were SGA. One patient had no mutation in ABCC8 and KCNJ11 gene. Genetic cause was not studied in six patients.
|Patients (n)||Mutations detected|
|ABCC8||3||p.E382K and p.R826W|
|PTF1A||2||g.23508437A>G distal enhancer|
|Thiamine responsive megaloblastic anemia||1||p.S214fs in SLC19A2|
|Wolcott Rallison syndrome||1||p.S718TfsX723 in EIF2AK3|
Conclusion: With high consanguinity ratio in this cohort, Wolcott Rallison syndrome was not the most common cause of NDM, contrary to previous reports. Male dominancy of our cohort was also noteworthy. In NDM patients with SGA and exocrine pancreatic deficiency PTF1A should be analysed first.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology