Phosphoglucomutase-1 deficiency: Early presentation, metabolic management and detection in neonatal blood spots

Mol Genet Metab. 2020 Sep-Oct;131(1-2):135-146. doi: 10.1016/j.ymgme.2020.08.003. Epub 2020 Sep 17.

Abstract

Phosphoglucomutase 1 deficiency is a congenital disorder of glycosylation (CDG) with multiorgan involvement affecting carbohydrate metabolism, N-glycosylation and energy production. The metabolic management consists of dietary D-galactose supplementation that ameliorates hypoglycemia, hepatic dysfunction, endocrine anomalies and growth delay. Previous studies suggest that D-galactose administration in juvenile patients leads to more significant and long-lasting effects, stressing the urge of neonatal diagnosis (0-6 months of age). Here, we detail the early clinical presentation of PGM1-CDG in eleven infantile patients, and applied the modified Beutler test for screening of PGM1-CDG in neonatal dried blood spots (DBSs). All eleven infants presented episodic hypoglycemia and elevated transaminases, along with cleft palate and growth delay (10/11), muscle involvement (8/11), neurologic involvement (5/11), cardiac defects (2/11). Standard dietary measures for suspected lactose intolerance in four patients prior to diagnosis led to worsening of hypoglycemia, hepatic failure and recurrent diarrhea, which resolved upon D-galactose supplementation. To investigate possible differences in early vs. late clinical presentation, we performed the first systematic literature review for PGM1-CDG, which highlighted respiratory and gastrointestinal symptoms as significantly more diagnosed in neonatal age. The modified Butler-test successfully identified PGM1-CDG in DBSs from seven patients, including for the first time Guthrie cards from newborn screening, confirming the possibility of future inclusion of PGM1-CDG in neonatal screening programs. In conclusion, severe infantile morbidity of PGM1-CDG due to delayed diagnosis could be prevented by raising awareness on its early presentation and by inclusion in newborn screening programs, enabling early treatments and galactose-based metabolic management.

Keywords: Congenital disorder of glycosylation; Dilated cardiomyopathy; Exercise intolerance; Galactose; Hypoglycemia; PGM1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cleft Palate / blood
  • Cleft Palate / complications
  • Cleft Palate / genetics
  • Congenital Disorders of Glycosylation / blood
  • Congenital Disorders of Glycosylation / complications
  • Congenital Disorders of Glycosylation / enzymology
  • Congenital Disorders of Glycosylation / genetics*
  • Dried Blood Spot Testing
  • Female
  • Glycogen Storage Disease / blood*
  • Glycogen Storage Disease / enzymology
  • Glycogen Storage Disease / genetics
  • Humans
  • Hypoglycemia / blood
  • Hypoglycemia / complications
  • Hypoglycemia / genetics*
  • Infant
  • Infant, Newborn
  • Male
  • Neonatal Screening
  • Phenotype
  • Phosphoglucomutase / blood*
  • Phosphoglucomutase / genetics

Substances

  • PGM1 protein, human
  • Phosphoglucomutase

Supplementary concepts

  • Glycogen Storage Disease XIV