Background Type 1 diabetes mellitus is the most common pediatric endocrine condition. Accounting for approximately 5–10% of all cases of diabetes. It is an autoimmune disease that leads to the destruction of insulin-producing pancreatic beta cells.requiring insulin replacement therapy. However, 68% of DM1 experience severe hypoglycemia per year. Could be related to high dose of insulin, decrease intake, celiac disease and adrenal insufficiency.

Case Report(s) 11 years old girl, diagnosed with DM1 since 2016. Started Insulin therapy multi daily injections (Aspart and degludec) dose range 0.8 to 1 units/kg/day. 2 years after diagnosis she started to have severe hypoglycemia with seizure requiring frequent hospitalization, sometimes she needed to stop use of insulin for days to weeks. Followed by a period of persistent hyperglycemia.

In 2019 she was referred to our hospital to control her diabetes. During her stay she developed hypoglycemia, insulin level was low, HbA1C was 11.7%, celiac profile was positive with high anti TGA 142, biopsy confirmed diagnosis of celiac disease, since then she was started on gluten free diet unfortunately our patient is not compliant to diet. adrenal insufficiency excluded by ACTHstimulation test, cortisol reached 900. Thyroid hormones give a picture of subclinical hypothyroidism and thyroid antibodies were positive, by 2021 her FT4 dropped to 11 started on levothyroxine. Later on Whole exome test results showed Heterozygous c.1411G>A (p.A471T) variant of unknown significance in cel gene. Causing AD, MODY type 8, pancreatic exocrine dysfunction, fecal elastase deficiency.

Stool elastase screening was negative.

Both parents were screened, mother has the same gene mutation. She is 32 years old and not diabetic. No family history of DM type 1 or 2.

Different types of insulin company were tried, open loop insulin delivery system and currently on closed loop insulin delivery system. But still with frequent hypoglycemia needed to interrupt the insulin pump.

Sep 2023 she was admitted for severe hypoglycemia, followed by persistent hyperglycemia, TIR was 22%, very high 95%, very low 4%, latest HbA1C done in September 2023 was 15.2%. We end up in keeping her in 2 profiles.First one is for hyperglycemia where she will have insulin basal 1 ml/hr, ICR 1:30, ISF 1:50, and another profile if mother noticed she will develop hypoglycemia insulin basal 0.3, ICR 1:50, ISF 1:400

Conclusion(s) This is a very challenging case, an unusual presentation of DM1, difficult to control.