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Review
. 2022 May 27;11(11):3027.
doi: 10.3390/jcm11113027.

Nonketotic Hyperglycinemia: Insight into Current Therapies

Magdalena Nowak  1 , Piotr Chuchra  1 , Justyna Paprocka  2
Affiliations
Review

Nonketotic Hyperglycinemia: Insight into Current Therapies

Magdalena Nowak et al. J Clin Med. .

Abstract

Nonketotic hyperglycinemia (NKH) is a rare inborn error of glycine metabolism that is characterized by the accumulation of glycine in all tissues, especially in the central nervous system (CNS). Based on clinical outcomes, NKH can be divided into two forms, i.e., severe and attenuated NKH. A poor prognosis, including no developmental progress and intractable epilepsy, is typical of severe NKH, whereas patients with the attenuated form present with varied symptoms and neurodevelopmental outcomes. So far, no causal treatment of NKH is known. Currently, the therapy is based on sodium benzoate and NMDA (The N-methyl-D-aspartate receptor) receptor site antagonists (dextromethorphan, ketamine). Different clinical outcomes of the therapy raise doubts about the effectiveness of the treatment. The purpose of this review is to summarize the therapeutic potential, challenges and effectiveness of different NKH therapies.

Keywords: NMDA antagonists; inborn error of metabolism; ketogenic diet; nonketotic hyperglycinemia; sodium benzoate; treatment; vagal nerve stimulation.

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Conflict of interest statement

The authors declare no conflict of interest.

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