title: A novel case of compound heterozygous congenital hyperinsulinism without high insulin levels.
abstract: BACKGROUND
  Congenital hyperinsulinism leads to unregulated insulin secretion and hypoglycemia. Diagnosis can be difficult and genetic testing may be warranted.
  
  
  METHODS
  This patient initially presented at 11 months with seizure activity secondary to severe hypoglycemia. Her diagnostic evaluation included genetic studies, which confirmed congenital hyperinsulinism. A novel combination of mutations in the ABCC8 gene leading to diffuse, diazoxide-unresponsive congenital hyperinsulinism was identified. Mutation analysis of ABCC8 showed three variants (R1215W - paternal, pathogenic; W739C - maternal, variant of unknown significance; R1393L - maternal, variant of unknown significance). Her clinical course continues to be complicated by severe, refractory hypoglycemia at age 3 years.
  
  
  CONCLUSIONS
  We describe a novel compound heterozygous mutation leading to diffuse, diazoxide-unresponsive congenital hyperinsulinism. This case illustrates challenges associated with diagnosing and managing congenital hyperinsulinism and the importance of genetic testing.
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229 USA.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Brady
authors.affiliation: Children's Hospital of Philadelphia, Division of Endocrinology, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104 USA.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Palladino
authors.affiliation: Cincinnati Children's Hospital Medical Center, Division of Endocrinology, 3333 Burnet Ave, MLC 7012, Cincinnati, OH 45229 USA.
authors.forename: Iris
authors.initials: I
authors.lastname: Gutmark-Little
keywords: ABCC8; Congenital hyperinsulinism; Diazoxide-unresponsive; Octreotide