ESPE Abstracts

Introduction: Hyperinsulinemic hypoglycemia (HH) is a clinically, genetically and morphologically heterogeneous group of diseases characterized by dysregulation of insulin secretion by pancreatic beta cells. HH may be associated with congenital, genetic, metabolic or syndromic causes. Here, a case in which Turner Syndrome (TS) and hyperinsulinemic hypoglycemia were detected together is presented due to its rarity.

Case: A ten month-old girl patient was referred due to detection of hypoglycemia while investigating the etiology of atonic seizure. In her medical history, she was born at 38 weeks with C/S and weighed 2285 grams, was diagnosed with congenital hypothyroidism and used LT4 therapy at a dose of 12.5 mg (5mg/kg/day). It was learned that she had been followed up in the neurology and developmental pediatrics departments since four months old due to nystagmus and neurodevelopmental delay. There was no feature in his family history. On physical examination, height:68cm (-2.67 SDS), body weight:7 kg (-2.46 SDS), body mass index:15.1 kg/m² (-1.14 SDS), head circumference:41,4cm(-3.46 SDS). She had nystagmus, mane neck, separated nipples, microcephaly and motor retardation depending on the month. In critical blood samples taken at the time of hypoglycemia (glucose:24 mg/dl), blood and urine ketone are negative, insulin:3.4 µIu/ml, growth hormone:1.31 ng/ml, cortisol:12.8 µg/dl. In the glucagon test, the blood sugar increase was 100 mg/dl and was compatible with hyperinsulinemic hypoglycaemia. Our patient was started on 10 mg/kg/day diazoxide and 2 mg/kg/day hydrochlorothiazide treatments. The patient, whose karyotype analysis was 45, X+mar(21)/45,X(30), was sent due to accompanying dysmorphic findings, and was diagnosed with Turner Syndrome. There was minimal pericardial effusion on echocardiography. There was no renal pathology in our patient's urinary system ultasonography (USG), gonads were observed in streak appearance in pelvic USG and FSH: 40.3 IU/L, LH:1.54 IU/L, Estradiol:<5 ng/L, AMH:<0.01 mg/L detected. Thyroid function tests were euthyroid, celiac autoantibodies were negative. Hearing and vision examinations were normal. Our patient's hydrochlorothiazide treatment was discontinued at the age of 3 years. Currently, diazoxide treatment is continued at a dose of 4.2 mg/kg/day, and monitoring for TS screening continues. Growth hormone replacement therapy will be planned according to growth monitoring.

Conclusion: HH is a rare endocrine finding in Turner Syndrome. The mechanisms involved in the dysregulation of insulin secretion in TS are not yet clear and require further research. Early diagnosis and appropriate clinical management are very important to prevent neurological sequelae caused by hypoglycemic attacks and seizures.

Key words: Hyperinsulinemic hypoglycemia, Turner Syndrome, diazoxide