Hyperinsulinism-hyperammonemia syndrome (HI/HA) (OMIM 606762), the second most common form of congenital hyperinsulinism (CHI) is associated with activating missense mutations in the GLUD1 gene, which encodes the mitochondrial matrix enzyme, glutamate dehydrogenase (GDH). Patients present with recurrent symptomatic postprandial hypoglycemia following protein-rich meals (leucine-sensitive hypoglycemia) as well as fasting hypoglycemia accompanied by asymptomatic elevations of plasma ammonia. In contrast to other forms of CHI, the phenotype is reported to be milder thus escaping recognition for the first few months of life. Early diagnosis and appropriate management are essential to avoid the neurodevelopmental consequences including epilepsy and learning disabilities which are prevalent in this disorder. We report an infant presenting with afebrile seizures secondary to hyperinsulinemic hypoglycemia resulting from a novel de novo mutation of the GLUD1 gene.
Symptoms of hypoglycemia were reported by 35.8% of patients with type 2 diabetes treated with oral antihyperglycemic agents in the Asia-Pacific region. Symptoms were severe in 11.6% and very severe in 8.2% of patients experiencing hypoglycemia.