Clinical picture of S-adenosylhomocysteine hydrolase deficiency resembles phosphomannomutase 2 deficiency

Mol Genet Metab. 2012 Nov;107(3):611-3. doi: 10.1016/j.ymgme.2012.08.014. Epub 2012 Aug 23.

Abstract

We report on the seventh known patient with S-adenosylhomocysteine hydrolase (SAHH) deficiency presenting at birth with features resembling phosphomannomutase 2 (PMM2-CDG Ia) deficiency. Plasma methionine and total homocysteine levels were normal at 2 months and increased only after the 8th month of age. SAHH deficiency was confirmed at 4.5 years of age by showing decreased SAHH activity (11% in both erythrocytes and fibroblasts), and compound heterozygosity for a known mutation c.145C>T (p.R49C) and a novel variant c.211G>A (p.G71S) in the AHCY gene. Retrospective analysis of clinical features revealed striking similarities between SAHH deficiency and the PMM2-CDG Ia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosylhomocysteinase / deficiency*
  • Adenosylhomocysteinase / genetics*
  • Congenital Disorders of Glycosylation / diagnosis*
  • Diagnosis, Differential
  • Erythrocytes / enzymology
  • Erythrocytes / pathology
  • Female
  • Fibroblasts / enzymology
  • Fibroblasts / pathology
  • Heterozygote
  • Homocysteine / blood
  • Humans
  • Infant, Newborn
  • Methionine / blood
  • Mutation*
  • Phosphotransferases (Phosphomutases) / deficiency

Substances

  • Homocysteine
  • Methionine
  • Adenosylhomocysteinase
  • Phosphotransferases (Phosphomutases)

Supplementary concepts

  • Congenital disorder of glycosylation type 1A