Hyperinsulinemic Hypoglycemia in a Patient with Costello Syndrome: An Etiology to Consider in Hypoglycemia

In this report, we describe a patient with CS accompanied by a clinical picture of hyperinsulinemic hypoglycemia responsive to diazoxide treatment. A 41-day-old female patient with a birth weight of 3,600 g was referred for atypical facial features and swallowing dysfunction. She had a weight of 4,000 g ( −0.8 SDS), a length of 50 cm (−2.4 SDS), and a head circumference of 38 cm (0.2 SDS). The clinical findings were suggestive of a genetic syndrome, mainly a RASopathy or Beckwith-Wiedemann syndrome. Whole exome sequencing revealed a de novo heterozygous missense variant in theHRAS (NM_001130442) gene in exon 2: c.35G#x3e;C; p.(Gly12Ala), establishing the molecular diagnosis of CS. The patient developed symptomatic hypoglycemia (jitteriness and sweating) at the age of 13 months. The patient ’s serum glucose was 38 mg/dL with simultaneous serum insulin and C-peptide levels, 2.8 μIU/mL and 1.8 ng/mL, respectively. Hyperinsulinism was suspected, and an exaggerated glucose response was detected in a glucagon test. Blood glucose monitoring indicated episodes of fasting hypoglycemia and p ostprandial hyperglycemia. Diazoxide of 10 mg/kg/day was initiated in 3 doses for hyperinsulinemic hypoglycemia, which resolved without new episodes of postprandial hyperglycemia. The patient deceased at the age of 17 months due to cardiorespiratory failure in the course of severe pneumonia complica ted with pulmonary hypertension and hypertrophic cardiomyopathy. Several genetic syndromes in...
Source: Molecular Syndromology - Category: Molecular Biology Source Type: research