Endocrine Abstracts

Case History: A 7 year old presented with 4 weeks of polyuria, polydipsia and one episode of nocturnal enuresis. The child’s past medical history was unremarkable, however, her parents reported that she was ‘less bright’ than her two siblings.

Initial assessment: The child appeared well. Urine dipstick testing showed 3+ glucose. Blood glucose was 17.5, blood ketones were 0.4 and blood gas values were within the normal range.

Results and treatment: The child was admitted to hospital overnight and commenced on the ‘walking wounded’ protocol (Levemir 0.2U/kg/bd, Novorapid 0.1U/kg with meals). At the time of hospital admission, HbA1c was 93 mmol/mol. Islet cell antibodies were >4,000 U/ml (normal range 0.0-7.5). Six weeks later whilst at home, she had an episode of transient limb weakness and abnormal posturing of her right arm. Her blood glucose was normal at the time of the episode. Cranial imaging was also normal. Four months later, she presented to hospital with disorientation, vomiting and intermittent abnormal posturing of her left arm. She was normoglycaemic with ketones of <0.4 at the time of these episodes. Lumbar puncture (carried out in a fasting state) showed a blood glucose of 17.2 and CSF glucose was 4 with a ratio of 0.23. Genetics results from an epilepsy gene panel showed a heterozygous likely pathogenic sequence variant in SLC2A1 gene (GLUT1 deficiency syndrome). A ketogenic diet, the treatment of choice in GLUT1 deficiency, was initiated with complexities in managing her diabetes with a higher glucose threshold and a tailored ketone plan. She commenced insulin hybrid closed loop pump therapy and has been stable from a neurocognitive perspective for 2 years.

Conclusion and points for discussion: GLUT1 deficiency syndrome is a rare condition and the likelihood of having this condition concurrently with T1DM is even rarer. The efficacy of ketogenic diets in GLUT1/epilepsy syndromes have been previously reported. Concurrent management of these two rare conditions has been complex but aided by hybrid closed loop therapy and individualisation of care.