Effective supplementation with folate, which prevents neural tube defect (NTD) occurrence, and high homocysteine levels in the blood of NTD children?s mothers suggest that genes involved in folate and homocysteine metabolism can be involved in NTD aetiology. Genes encoding methylenetetrahydrofolate reductase (MTHFR) or methylenetetrahydrofolate dehydrogenase (MTHFD) belong to the first group. Genes encoding methionine synthase (MTR), its regulator ? methionine synthase reductase (MTRR) and also cystathionine synthase (CBS) can be included in the second group. We present a current list of the folate and homocysteine metabolism genes that are known to be involved in NTD and pay special attention to primary and secondary NTD prevention.
The birth incidence of neural tube defect (NTD) cases in British Columbia (B.C.), and elsewhere in North America, is reported to be declining. This decline is being attributed to folic acid (FA) supplementation and food fortification, but 2nd trimester prenatal screening of pregnancies for NTDs and other congenital anomalies has increased during this timeframe, as well. This descriptive, population-based study evaluates the impact of prenatal screening of NTD-affected pregnancies on (1) pregnancy outcome and (2) reporting of NTD births to the provincial Health Status Registry (B.C.H.S.R.); and it assesses (3) the use of periconceptional FA supplementation. NTD cases were ascertained from medical records of health centres providing care to families with NTD-affected pregnancies and newborns; and from NTD cases reported to the B.C.H.S.R. In 1997?1999, the B.C.H.S.R. published a NTD incidence of 0.77/1000. In this study, 151 NTD-affected pregnancies were identified, with an incidence of 1.16/1000. Partial Reporting of induced abortions in a NTD incidence 45.5% low than the actual incidence. Medical records were available for review on 144/151 pregnancies. Prenatal screening identified 86.1% (124/144) of NTD-affected pregnancies, with 72.6% (90/124) resulting in pregnancy termination, and 27.4% (34/124) continuing to term. Use of FA supplementation in the periconceptional period was recorded in 36.4% of pregnancies (39/107). Thus in B.C. the decline in the NTD incidence is due predominantly to pregnancy terminations following prenatal diagnosis, which reduces the NTD incidence by 60%, from 1.16/1000 to 0.47/1000. Continued efforts for primary and the option of secondary prevention of NTDs are recommended in order to improve newborn health in B.C. and elsewhere. These interventions need to be monitored, however, for optimal health care planning.
Periconceptional folic acid supplementation is recommended to prevent congenital malformations, mainly neural tube defects, but only 7% of pregnant women in Saxony-Anhalt (Germany) take folic acid at least 4 weeks before conception and in the first 3 months of pregnancy. From March to June 2004, we sent standardized questionnaires about folic acid and its importance during pregnancy to 33 schools in the Federal State of Saxony-Anhalt. A total of 4332 young people aged 1521 years completed the questionnaire, of which 2632 were girls (61%) and 1685 were boys (39%). The majority of them (61%) had heard about folic acid, but only 5% knew that it is a vitamin and 0.7% were aware of the physiological functions of folic acid. Only 22% of the young people answered that folic acid should be taken before and during pregnancy, whereas almost all respondents knew other precautions during pregnancy, e.g. 'no smoking' and 'no alcohol'. Our survey shows that the level of awareness of the importance of folic acid at schools is very low. We suggest that the problem of folic acid should be included in the curricula of biology classes at schools to spread the knowledge of this subject among young people.
We analyzed the role of the C677T polymorphism of the 5,10-methylenetetrahydrofolate and the A66G polymorphism of the methionine synthase reductase genes as risk factors for occurrence of spina bifida. The studied population included 106 mothers and 104 children from affected families, and a control group of 100 adults. We found statistically significant differences between the occurrence of the homozygosity in these polymorphisms in the groups of mothers and children with thoracolumbal defects (C677T polymorphism) and lumbosacral defects (A66G polymorphism). We postulate that these polymorphisms should be regarded as independent risk factors for spina bifida.
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