Are common mutations of cystathionine beta-synthase involved in the aetiology of neural tube defects?

Clin Genet. 1997 Jan;51(1):39-42. doi: 10.1111/j.1399-0004.1997.tb02412.x.


Mildly elevated maternal plasma homocysteine (Hcy) levels (hyperhomocysteinemia) have recently been observed in some neural tube defect (NTD) pregnancies. Plasma levels of Hcy are governed by both genetic and nutritional factors and the aetiology of NTDs is also known to have both genetic and nutritional components. We therefore examined the frequency of relatively common mutations in the enzyme cystathionine beta-synthase (CBS), which is one of the main enzymes that controls Hcy levels, in the NTD population. Neither the severely dysfunctional G307S CBS allele nor the recently reported 68 bp insertion/I278T CBS allele was observed at increased frequency in the cases relative to controls. We therefore conclude that loss of function CBS alleles do not account for a significant proportion of NTDs in Ireland.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cystathionine beta-Synthase / genetics*
  • DNA Transposable Elements
  • Female
  • Gene Frequency
  • Haplotypes
  • Heterozygote
  • Homocysteine / blood*
  • Homozygote
  • Humans
  • Infant, Newborn
  • Ireland
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Mutation*
  • Neural Tube Defects / epidemiology
  • Neural Tube Defects / genetics*
  • Oxidoreductases Acting on CH-NH Group Donors / genetics*
  • Polymerase Chain Reaction
  • Pregnancy
  • Risk Factors
  • Sequence Analysis, DNA


  • DNA Transposable Elements
  • Homocysteine
  • Oxidoreductases Acting on CH-NH Group Donors
  • Methylenetetrahydrofolate Reductase (NADPH2)
  • Cystathionine beta-Synthase