Clinical and molecular data from 61 Brazilian cases of Congenital Hyperinsulinemic Hypoglycemia

Abstract

ObjectiveTo study the clinical and molecular characteristics of a sample of Brazilian patients with Congenital Hyperinsulinemic Hypoglycemia (CHH).MethodsElectronic message was sent to members from Endocrinology Department- Brazilian Society of Pediatrics requesting clinical data for all cases of CHH. A whole blood sample from living patients was requested for DNA extraction followed by a search for mutations of the genes ABCC8, KCNJ11, GCK, GLUD1, HADH, SLC16A1 and HNF4A.ResultsOf the 61 patients evaluated, 36 (59%) were boys, and only 16 (26%) were born by normal delivery. Gestational age ranged from 32 to 41 weeks (mean = 37 weeks and 6 days). Birth weight ranged from 1590 to 5250 g (mean = 3430 g). Macrossomia occurred in 14 cases (28%). Age at diagnosis ranged from 1 to 1080 days (mean = 75 days). DNA for molecular analysis was obtained from 53 of the 61 patients. Molecular changes in the ABCC8 gene were detected in 15 (28%) of these 53 cases, and mutations in the KCNJ11 gene were detected in 6 (11%). Mutations in the GLUD1 gene were detected in 9 cases (17%) of the total series. Mutations of the GCK gene in heterozygosis were detected in 3 cases. No mutations were detected in the sequencing of genes HADH, SLC16A1 and HNF4A.ConclusionThe present study conducted in Brazil permitted the collaborative compilation of an important number of CHH cases and showed that the present clinical and molecular data are similar to those of published global series.

Neonatal Hypoglycemia

“…Nine genes have been identified and classified within the potassium channelopathies (ABCC8, KCNJ11) and metabolic disorders (GLUD1, GCK, HNF4A, HNF1A, SLC16A1, UCP2, HADH) [47,52]. Genetic defect mutations involving the ABCC8/KCNJ11 genes, which encode the SUR1/Kir 6.2 components of the ATP-sensitive potassium channels (K ATP ) in pancreatic beta cells, are the most common [13,27]. In normal cells, the K ATP channels remain open or closed in response to variation in blood glucose levels, which leads to changes in the action potential of the cell membrane.…”