565-P: A Case of Atypical Diabetes, Monogenic Diabetes

A Case of Atypical Diabetes, Monogenic Diabetes, Monogenic diabetes formerly known as maturity onset diabetes of the young (MODY) is typically diagnosed in younger patients, usually age <25 years. It is a heterogenous disorder and typically accounts for 2-5% of diabetes. Clinical findings tend not to be reliable in determining the underlying etiology, hence patients may be misdiagnosed as type 1 or type 2 diabetes mellitus (DM). Patient is a 42-year-old non-obese male (BMI 21.9) with past medical history of type 2 diabetes mellitus who presented to establish care. He was diagnosed at age 25 with type 2 diabetes. At presentation, he had a hemoglobin A1c of 12.4% and was being managed with metformin, glimepiride and semaglutide by his primarry care physician. He has never been developed diabetes ketoacidosis or been on insulin. Also, his BMI has always been <25. He endorsed an extensive family history of DM but none of them require insulin or are overweight. His father, mother, brother, paternal grandfather and grandmother all have type 2 DM, most mainly diagnosed in their twenties and thirties. Laboratory studies including c-peptide and islet cell autoantibody screen panel were obtained which were low-normal (0.7ng/ml) and negative respectively. Repeat C-peptide was normal at 3.1ng/ml. Given these findings and his extensive family history of DM in non-obese persons, MODY was suspected. Hence genetic testing was done and revealed a heterogenous mutation, ABCC8 Variant in KATPase consistent with MODY12. This variant is typically sulfonylurea responsive. No screening test currently exists for monogenic diabetes. This case demonstrates the misdiagnosis of monogenic diabetes and the need for updated screening guidelines to aid with early diagnosis to prevent the associated comorbidities. Also, early diagnosis will prompt genetic testing in patients off springs and aid in adequate treatment. Finally, the value of a comprehensive history cannot be overemphasized in aiding to make a diagnosis of monogenic diabetes Disclosure R.Attah: None.