ESPE Abstracts (2016) 86 RFC9.5

Non-Mody Monogenic Diabetes: A Very Heterogenous and Problematic Group of Diabetes

Zeynep Siklara, Elisa De Francob, Sarah FlanagaNb, Sian Ellardb, Serdar Ceylanerc, Kaan Boztugd, Figen Dogue, Aydan Ikinciogullarif, Zarife Kulogluf, Aydan Kansue & Merih Berberoglua

aDepartment of Pediatric Endocrinology, Ankara University School of Medicine, Ankara, Turkey; bUniversity of Exeter Medical School, Exeter, UK; cIntergen Genetic Center, Ankara, Turkey; dCeMM Research Center, Vienna, Austria; eDepartment of Immunology and Allergy, Ankara University School of Medicine, Ankara, Turkey; fDepartment of Pediatric Gastroenterology, Ankara University School of Medicine, Ankara, Turkey

Background: Monogenic diabetes represents a group of disorders resulting from a single gene defect leading to disruption of insulin secretion or a reduction in the number of beta cells. Despite the classification of monogenic diabetes according to age of onset, with neonatal DM (<6 months of age) and maturity onset diabetes of young (MODY) (>6 months and <25 years of age); not every case can be classified into those groups.

Objective and hypotheses: We aim to evaluate non-MODY monogenic diabetes diagnosed in our clinic, and emphasize the characteristics of patients.

Method: We evaluated the patients with monogenic diabetes, during the last 10 years period. Type 1 DM, MODY, and patients with negative autoantibodies and no mutation were excluded from the study.

Results: Twelve patients, aged 1 days to 11 years, were diagnosed with non-MODY monogenic diabetes. Half the patients were diagnosed after 6 months of age. Most patients had a KATP channel defect. Disruption of beta cells was detected in 6 patients, with 3 cases having a WFS1 mutation, 3 had positive autoantibodies (2 an LRBA mutation, and one CD25 deficiency). Additional systemic findings including severe immune system dysfunction were seen in 6/12 patients (Table). Treatment with sulphonylurea was succesful in two patients with an ABCC8 gene mutation. The other patients were given insulin in very heterogenous doses (0.4–1.6 U/Kg body weight). Four patients died during follow-up, three of which had immune dysfunction.

Conclusion: Monogenic diabetes due to a mutation in a non-MODY gene can be diagnosed after 6 months of age. Even with positive autoantibodies. Immune dysfunction was present in 50% of patients in our cohort and should be investigated in all patients with early-onset monogenic diabetes. Mortality of patients with monogenic diabetes and additional autoimmunity was high in our cohort and is likely to reflect the multisystem nature of these diseases.