Nonketotic Hyperglycinemia: Proposal of a Diagnostic and Treatment Strategy

Pediatr Neurol. 2010 Sep;43(3):221-4. doi: 10.1016/j.pediatrneurol.2010.04.018.


Early myoclonic encephalopathy presents neonatally with fragmented myoclonus and a suppression-burst electroencephalography pattern. We describe a newborn boy with early myoclonic encephalopathy caused by nonketotic hyperglycinemia. He presented with severe hypotonia, progressive apneic episodes, and erratic myoclonus. Screening of deletions in GLDC, using the multiplex ligation-dependent probe amplification method, and a (13)C breath test confirmed the diagnosis of nonketotic hyperglycinemia. Treatment with the N-methyl-d-aspartate receptor antagonist ketamine exerted dramatic suppressive effects on his seizures, and ameliorated his clinical status.

Publication types

  • Case Reports

MeSH terms

  • Glycine / blood
  • Glycine / cerebrospinal fluid
  • Humans
  • Hyperglycinemia, Nonketotic / blood
  • Hyperglycinemia, Nonketotic / cerebrospinal fluid
  • Hyperglycinemia, Nonketotic / diagnosis*
  • Hyperglycinemia, Nonketotic / therapy*
  • Infant, Newborn
  • Male


  • Glycine