Syndromes, disorders and maternal risk factors associated with neural tube defects (VI)

The VANGL1 P384R variant cause both neural tube defect and Klippel-Feil syndrome

Background

Neural tube defect (NTD) is a common birth defect causing much death in the world. Variants in VANGL1 lead to NTD and caudal regression syndrome. NTD displays a complex phenotype encompassing both genetic and environmental factors.

Methods

The fetus was diagnosed by prenatal ultrasound examination. Postnatal CT and autopsy were performed. Genetic testing was conducted in the family and Sanger sequencing was validated. Multiple prediction soft‐wares were used to predict the pathogenicity of the variant.

Results

The VANGL1 gene variant c.1151C>G (P384R) was detected in a fetus diagnosed with tethered spinal cord and sacrococcygeal lipoma. The VANGL1 variant c.1151C>G (P384R) was reported in a Klippel‐Feil syndrome patient. The VANGL1 variant was validated in the trio‐family but the mother showed no abnormalities.

Conclusion

Overall, this study presents fetal NTD caused by the same VANGL1 variant found in a Klippel‐Feil syndrome patient with complete clinical information of prenatal ultrasound, postnatal CT, and genetic results as early as 25 GW. Our study not only expands the VANGL1 mutational spectrum but also sheds light on the important role of the VANGL1 P384R variant in human development.

Maternal zinc deficiency and congenital anomalies in newborns

BACKGROUND

Zinc deficiency in pregnant women is common, especially in the third trimester of pregnancy. The available data, however, on the association between zinc deficiency and congenital malformations in the Iranian population are insufficient. The aim of this study was therefore to determine whether maternal serum zinc deficiency is associated with major congenital malformations in newborns.

METHODS

This descriptive, case-control study involved mothers of 80 neonates with congenital anomalies (study group) admitted to the Mofid Children's Hospital, Tehran, Iran. During the same period (2014 and 2015), serum zinc was measured in 80 mothers who had delivered normal newborns without congenital malformations (control group).

RESULTS

Mothers with serum zinc deficiency had a more than sevenfold risk of malformations in the fetus compared with mothers with normal serum zinc (OR, 7.013; 95%CI: 2.716-18.110). Newborns with malformation weighing ≤2500 g were associated with lower maternal serum zinc compared with the control group (P = 0.006).

CONCLUSIONS

There is an association between congenital malformation in newborns and maternal zinc deficiency.

Effect of rotating shift work on childbearing and birth weight: a study of women working in a semiconductor manufacturing factory

BACKGROUND

Stable circadian rhythm is important for both maternal and fetal health. This retrospective analysis of women in a semiconductor factory evaluated the effect of shift work exposure on childbearing and birth weight.

METHODS

Records of 440 female employees (initial mean age: 28.4 years) including 111 mothers who had 158 live births during the period of observation (1997-2007) were reviewed. The data analyzed included maternal age, general health condition, highest educational level, life-style and occupational factors, as well as newborn gender, birth weight, birth order and gestational age.

RESULTS

The childbearing rates of female workers on three different work schedules (consistent daytime work (CDW), intermittent (i-) or persistent (p-) rotating shift works (RSW)) were 32.1%, 20.0% and 25.4%, respectively (P=0.047). After controlling for potential confounding factors, childbearing rates among women with CDW exceeded those of shift workers (odds ratio (OR), 1.7; 95% confidence interval (CI), 1.0-3.0). The birth weights of newborns from mothers on the three work schedules (CDW, i-RSW and p-RSW) were significantly different (3271.7±395.4, 3251.3±460.9, and 2998.5±381.2 g, respectively (P<0.01). Newborns within the lightest birth weight quintile were significantly more likely to be born to mothers with exposure to p-RSW (OR, 4.3; 95% CI, 1.1-16.8).

CONCLUSIONS

Rotating shift work exposure was significantly associated with decreased childbearing and lighter birth weight in women working in this semiconductor manufacturing factory. Work schedules should be carefully planned for female employees who are pregnant or preparing for pregnancy. Prenatal evaluations for mothers with persistent day-night rotating shift work exposures are especially necessary.

The plausibility of maternal nutritional status being a contributing factor to the risk for fetal alcohol spectrum disorders: the potential influence of zinc status as an example

There is increasing evidence that human pregnancy outcome can be significantly compromised by suboptimal maternal nutritional status. Poor diet results in a maternal-fetal environment in which the teratogenicity of other insults such as alcohol might be amplified. As an example, there is evidence that zinc (Zn) can interact with maternal alcohol exposure to influence the risk for fetal alcohol spectrum disorders (FASD). Studies with experimental animals have shown that the teratogenicity of alcohol is increased under conditions of Zn deficiency, whereas its teratogenicity is lessened when animals are given Zn-supplemented diets or Zn injections before the alcohol exposure. Alcohol can precipitate an acute-phase response, resulting in a subsequent increase in maternal liver metallothionein, which can sequester Zn and lead to decreased Zn transfer to the fetus. Importantly, the teratogenicity of acute alcohol exposure is reduced in metallothionein knockout mice, which can have improved Zn transfer to the conceptus relative to wild-type mice. Consistent with the above, Zn status has been reported to be low in alcoholic women at delivery. Preliminary data from two basic science and clinical nutritional studies that are ongoing as part of the international Collaborative Initiative on Fetal Alcohol Spectrum Disorders support the potential role of Zn, among other nutritional factors, relative to risk for FASD. Importantly, the nutrient levels being examined in these studies are relevant to general clinical populations and represent suboptimal levels rather than severe deficiencies. These data suggest that moderate deficiencies in single nutrients can act as permissive factors for FASD, and that adequate nutritional status or intervention through supplementation may provide protection from some of the adverse effects of prenatal alcohol exposure.

Alcohol abuse in pregnant women: effects on the fetus and newborn, mode of action and maternal treatment

Offspring of mothers using ethanol during pregnancy are known to suffer from developmental delays and/or a variety of behavioral changes. Ethanol, may affect the developing fetus in a dose dependent manner. With very high repetitive doses there is a 6-10% chance of the fetus developing the fetal alcoholic syndrome manifested by prenatal and postnatal growth deficiency, specific craniofacial dysmorphic features, mental retardation, behavioral changes and a variety of major anomalies. With lower repetitive doses there is a risk of "alcoholic effects" mainly manifested by slight intellectual impairment, growth disturbances and behavioral changes. Binge drinking may impose some danger of slight intellectual deficiency. It is advised to offer maternal abstinence programs prior to pregnancy, but they may also be initiated during pregnancy with accompanying close medical care. The long term intellectual outcome of children born to ethanol dependent mothers is influenced to a large extent by the environment in which the exposed child is raised.