Pancreatic beta-cell stimulation tests in transient and persistent congenital hyperinsulinism.
In congenital hyperinsulinism (HI). the in vivo pancreatic beta-cell function is poorly described. Among 14 neonates with severe hyperinsulinaemic hypoglycaemia, 2 patients had very prolonged or persistent hypoglycaemia and mutation in the sulphonylurea receptor SURI gene. Patient 1 had transient HI and was treated medically for 3.5 mo before clinical remission was seen. He had initially very high basal and stimulated C-peptide and insulin levels, followed by a state of normal preprandial values, but blunted beta-cell glucose sensitivity, before complete beta-cell normalization occurred. A single. paternal SURI mutation, G1382S, was found suggesting focal type HI. Patient 2 had persistent HI and underwent 3 pancreas resections up to the age of 2 y, 7 mo, followed by a state of mild diabetes. On biopsy, diffuse-type beta-cell hypertrophy was seen. The beta-cell response to glucose and glucagon stimulation was blunted before, as well as after, pancreas resections. Compound heterozygosity for the SUR1 mutations 3992-3c to g and N188S was found.


CONCLUSIONS
Transient, possibly focal, HI with paternal SUR1 mutation was associated with a gradual, but complete normalization of the in vivo beta-cell function; in the diffuse type HI, a blunted beta-cell response to glucose and glucagon stimulation persisted. In vivo beta-cell stimulation tests may contribute to the characterization of the HI subtypes.
Christesen
H B
HB
Department of Paediatrics, Odense University Hospital, Denmark. thybo@dadlnet.dk
Feilberg-Jørgensen
N
N
Jacobsen
B B
BB
D002675:Child, Preschool; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000151:congenital* / Q000175:diagnosis* / Q000503:physiopathology; D007223:Infant; D007231:Infant, Newborn; D007515:Islets of Langerhans / Q000503:physiopathology*; D008297:Male; D010186:Pancreatic Function Tests