In addition, transcription factors, as well as genes involved in mitosis, actin regulation, and methylation appear to be implicated in the causes of NTDs.
The risk of an open neural tube defect or other serious fetal abnormality was 60% when alpha-fetoprotein levels measured greater than or equal to +3 and 86% for levels greater than or equal to +5 SD.
A severe neural tube defect diagnosed in a 191/2-week-old "at risk" fetus on the evidence of a markedly elevated alpha-fetoprotein level in the amniotic fluid, turned out to be an occipital myelocoele.
In an attempt to identify biochemical components of the genetic predisposition to neural tube defects (NTDs), levels of folate, cobalamin, apo-transcobalamins I and II and alpha-fetoprotein were studied in midtrimester amniotic fluid from 24 pregnant women who had previously had a child with NTD.
Routine maternal serum alpha-fetoprotein screening for neural tube defects, and now also for aneuploidy, is a classic example in which there has been a schism between the clinical expertise to manage such a program within a tertiary level reproductive genetics center and the ability to reach patients in regions that are not routinely accessible to the tertiary center.
To establish gestational age-specific and body weight-specific mid-trimester normal median equations for the prenatal serum markers α-fetoprotein (AFP), free β subunit human chorionic gonadotropin (fβHCG), and unconjugated oestriol (uE3) for a Chinese population; to compare and replace the median equations built in LifeCycle software; to evaluate the effect of equations used for gestation correction on estimating risk in Down's syndrome, Edward's syndrome, and neural tube defect (NTD).A total of 353,065 cases of prenatal screening data of pregnant women were screened by 13 prenatal screening institutions in China.
The diagnosis of fetal triploidy should be considered when there is a very high maternal serum alpha-fetoprotein and no ultrasound evidence of open neural tube defect, ventral wall defect, or any other explanation.
Neural tube defects are associated with an increase of AFP in amniotic fluid, but, as in normal pregnancies, the values decrease with increasing gestational age.
The increased frequency of hydrocephalus among sibs of probands with a NTD and vice versa suggests that, following the birth of a child with either malformations, subsequent pregnancies should be monitored at mid-gestation by amniotic fluid AFP and serial ultrasound examination.
We detected neural tube defects (0.2%) as expected but were surprised by the efficacy with which low serum alpha-fetoprotein values identified aneuploid fetuses.
Blood samples were collected from 534 mothers of fetuses or newborns with NTDs and 534 control mothers who had healthy term newborns and were assayed for 12 polymorphisms in the AHR and cytochrome P450 (CYP) genes.
Of the secondary tests performed, ARID1A rs11247593 was associated with NTDs in whites, and ALDH1A2rs7169289 was associated with isolated NTDs in African Americans.
The CT genotype and C allele of rs2276731 in ALDH1L1 significantly were associated with an increased incidence of NTDs (OR = 1.67, 95 % CI 1.129-2.491 with genotype, and OR = 1.32, 95 % CI 0.956-1.816 with allele).The polymorphic loci rs4646733, rs2305225, and rs2276731 in the ALDH1L1 gene maybe potential risk factors for NTDs in the Chinese population.
Mutations in transcriptional co-activator genes-Cited2, p300, Cbp, Tfap2α, Carm1 and Cart1 result in NTDs in murine models, thus prompt us to investigate whether homologues of these genes are associated with NTDs in humans.
In genetic NTD models such as Cart1, splotch, Cited2, and crooked tail, and NTD induced by teratogens including valproic acid and fumonisins, the incidence of defects is reduced by maternal folic acid supplementation.
Possibly damaging variants were observed in SCZ: A203V, S801N in GLDC, near the atypical nonketotic hyperglycinemia causative mutations (A202V, A802V); G825D in GLDC, a potential neural tube defect causative mutation; and R253X in AMT.