Congenital disorder of glycosylation id presenting with hyperinsulinemic hypoglycemia and islet cell hyperplasia.
BACKGROUND
Inborn errors in protein glycosylation, such as the congenital disorders of glycosylation (CDGs), generate multifaceted syndromes that impair many organ systems. We here report the diagnosis of the third known patient with CDG-Id.


RESULTS
The patient's phenotype was extremely severe, and she succumbed at 19 d of age. Leading features included hyperinsulinemic hypoglycemia, and autopsy revealed islet cell hyperplasia with increased beta-cell mass. Other features were a Dandy-Walker malformation, facial dysmorphisms, and profound hypotonia. The patient carried a novel homozygous point mutation (512G>A) in the hALG3 gene, which encodes a mannosyltransferase. Lentiviral complementation with wild-type hALG3 corrects the biochemical defect in the patient's fibroblasts.


CONCLUSIONS
Our findings underscore the importance of proper glycosylation in several major organ systems and emphasize that CDG should be ruled out in patients with persistent hyperinsulinemic hypoglycemia of unknown etiology.
Sun
Liangwu
L
The Burnham Institute, Program for Glycobiology and Carbohydrate Chemistry, 10901 North Torrey Pines Road, La Jolla, California 92037, USA.
Eklund
Erik A
EA
Chung
Wendy K
WK
Wang
Chao
C
Cohen
Jason
J
Freeze
Hudson H
HH
D000328:Adult; D002478:Cells, Cultured; D005260:Female; D006031:Glycosylation; D006801:Humans; D006946:Hyperinsulinism / Q000235:genetics*; D006965:Hyperplasia; D007003:Hypoglycemia / Q000235:genetics*; D007150:Immunohistochemistry; D007231:Infant, Newborn; D007515:Islets of Langerhans / Q000473:pathology*; D008364:Mannosyltransferases / Q000235:genetics*; D008661:Metabolism, Inborn Errors / Q000235:genetics*; D011247:Pregnancy
C489947:ALG3 protein, human; D008364:Mannosyltransferases