6561 Assessing risk of monogenic diabetes in paediatric patients with type 1 diabetes

Objectives Monogenic Diabetes in CYP comprises a group of single gene defects that mimics type 1 diabetes or type 2 diabetes. Lack of knowledge, non-availability and cost of genetic testing are important factors resulting in delay in definitive diagnosis.1 Diagnosis is essential for specific treatment (e.g., oral sulfonylureas) or withdrawing all insulin therapy (e.g., in Glucokinase gene mutations)2 and appropriate counselling about risk in offspring.3 NHS Genomic Medicine Service offers Monogenic Diabetes Genetic Screen for patients who fulfil certain criteria (R141–3).4 It is unclear how many with Monogenic Diabetes are being treated as Type 1 Diabetics. We designed this study to review data of CYP with type 1 diabetes looked after in a medium sized DGH to identify which are likely to have Monogenic Diabetes. Methods Electronic records of CYP with type 1 diabetes looked after by Paediatric Diabetes Team in Walsall Healthcare NHS Trust were reviewed. We extracted current age, age at diagnosis, diabetes treatment, family history of diabetes, ethnicity, body mass index, HbA1c at time of diagnosis, and the antibody test results for these patients. This data was used to test these patients against NHS England Genomics criteria and including use of Exeter MODY calculator in patients where antibody results were available. Results We looked at 167 CYP with type 1 diabetes at our hospital. 82.6% had autoantibodies tested. 25 patients tested negative for anti-GAD antibodies and we ran them through the Exeter Diabetes MODY Probability Calculator. Out of these 25 patients, 17 (68%) were male, and the average age at diagnosis was 8 years (± 3.96 years). 22 patients were Caucasians. 9 patients tested negative for anti-islet cell antibodies and report not available for 4 patients. Only two had parents affected with diabetes. Only 1 patient (non-caucasian) had a significant probability of 49.4% on MODY calculator and 10 patients had a probability of Conclusion The results showed one case out of the total patients may have Monogenic Diabetes. Since autoantibody screen is not offered to all newly diagnosed diabetics, it was difficult to assess all patient data for Monogenic Diabetes risk. We propose that the one patient identified be offered Monogenic Diabetes Genetic screen and a wider discussion to be held in Paediatric Diabetologists Community about value of offering autoantibody testing to all patients newly diagnosed with diabetes. References Thanabalasingham, G; Huffman, JE; Kattla, JJ; Novokmet, M; Rudan, I; Gloyn, A; Hayward, C; Adamczyk, B; Reynolds, R; Muzinic, A; et al. Mutations in HNF1A Result in Marked Alterations of Plasma Glycan Profile. Diabetes 2012;62:1329–1337. Timsit, J; Saint-Martin, C; Dubois-Laforgue, D; Bellanne-Chantelot, C. Searching for Maturity-Onset Diabetes of the Young (MODY): When and What for? Can. J. Diabetes 2016;40:455–461. Amed, S; Oram, R. Maturity-onset diabetes of the young (mody): making the right diagnosis to optimize treatment. Can. J. Diabetes 2016;40:449–454. https://www.diabetesgenes.org/tests-for-diabetes-subtypes/guidelines-for-genetic-testing-in-mody/