Health and developmental outcome of children following prenatal diagnosis of confined placental mosaicism

Objective To determine the long-term health and development of a cohort of children in whom confined placental mosaicism (CPM) was diagnosed at prenatal diagnosis. Methods A retrospective cohort study was performed comparing 36 children in whom CPM had been diagnosed prenatally with 195 controls subjects in whom a normal karyotype had been detected prenatally. Data comprising birth information, health, health service utilisation, growth, development, behaviour, and the family were collected by a maternal questionnaire administered when the subjects were aged between 4 and 11 years. Results CPM cases did not differ from controls across a broad range of health measures and there were no major health problems or birth defects among the CPM group. No increase was detected in the incidence of intrauterine growth retardation (IUGR) among CPM cases; however, postnatal growth was reduced compared with controls (p = 0.047). Development and behaviour in CPM cases was similar to that of controls. Conclusions The prenatal diagnosis of CPM is not associated with an increased risk of birth defects or developmental problems, but may be associated with decreased growth. Copyright (C) 2006 John Wiley & Sons, Ltd.

Authors' institutional affiliations in Australian intellectual and developmental disabilities journals: a comparison of two decades

The generation of new knowledge through research can contribute significantly to the improvement of services for individuals with intellectual and developmental disabilities. This study extends a previous study by Sigafoos, Roberts, and Couzens [Aust. N.Z.J. Dev. Disabil. 17 (1991) 331] by examining research productivity in intellectual and developmental disability in Australian journals for 1990-1999. Institutions that published research articles on intellectual and developmental disabilities in Australian journals in the 1990s were identified by noting the affiliations of authors. The most productive institutions were primarily universities in Australia and the United States of America. Publication trends in the decade of the 1990s are compared with trends of the previous decade (1980-1990). (C) 2003 Published by Elsevier Ltd.

Family violence: Walking the tight rope between maternal alienation and child safety

Mothers are often alienated from their children when child abuse is suspected or confirmed, whether she is the primary abuser of the child or not. An abusive or violent partner often initiates the process of maternal alienation from children as a control mechanism. When the co-occurrence of maternal and child abuse is not recognised, nurses and health professionals risk further alienating a mother from her children, which can have detrimental effects in both the short and long term. Evidence shows that when mothers are supported and have the necessary resources there is a reduction in the violence and abuse she and her children experience; this occurs even in situations where the mother is the primary abuser of her children. The family-centred care philosophy, which is widely accepted as the best approach to nursing care for children and their families, creates tension for nurses caring for children who are the victims of abuse as this care generally occurs away from the context of the family. This fragmented approach to caring for abused children can inadvertently undermine the mother-child relationship and further contribute to maternal alienation. This paper discusses the complexity of family violence for nurses negotiating the 'tight rope' between the prime concern for the safety of children and further contributing to maternal alienation, within a New Zealand context. The premise that restoration of the mother-child relationship is paramount for the long-term wellbeing of both the children and the mother provides the basis for discussing implications for nursing practice.

In utero and postnatal maternal smoking and asthma in adolescence

Background: Asthma in early childhood has been associated with maternal smoking during pregnancy and parental smoking soon after birth. However, less is known about these exposures and the development of asthma symptoms in adolescence. Methods: Data were taken from the Mater University Study, of Pregnancy, a large birth cohort study of mothers and children enrolled in Brisbane, Australia, beginning in 1981. Smoking was assessed at 2 stages during pregnancy and at the 6-month and 5-year follow-up visits. Asthma was assessed from maternal reports that were provided when the child was age 14 years. We conducted multivariable multinomial logistic regression analyses to assess the effect of maternal smoking on asthma symptoms. Results: There was a strong sex interaction such that girls whose mothers had smoked heavily (20 or more cigarettes per day) in pregnancy and at the 6-month follow up had increased odds of experiencing asthma symptoms at age 14 (odds ratio = 1.96; 95% confidence interval = 1.25-3.08). The contribution of heavy smoking during pregnancy appeared to be stronger than heavy smoking after the birth. No similar associations were seen for boys. Conclusion: Female adolescents whose mothers smoked heavily during the fetal period and the early months of life have increased risk of asthma symptoms in adolescence. In utero exposure to heavy smoking was found to have a stronger effect than postnatal environmental tobacco exposure.

The v-MFG test: Investigating maternal, offspring and maternal-fetal genetic incompatibility effects on disease and viability

The MFG test is a family-based association test that detects genetic effects contributing to disease in offspring, including offspring allelic effects, maternal allelic effects and MFG incompatibility effects. Like many other family-based association tests, it assumes that the offspring survival and the offspring-parent genotypes are conditionally independent provided the offspring is affected. However, when the putative disease-increasing locus can affect another competing phenotype, for example, offspring viability, the conditional independence assumption fails and these tests could lead to incorrect conclusions regarding the role of the gene in disease. We propose the v-MFG test to adjust for the genetic effects on one phenotype, e.g., viability, when testing the effects of that locus on another phenotype, e.g., disease. Using genotype data from nuclear families containing parents and at least one affected offspring, the v-MFG test models the distribution of family genotypes conditional on offspring phenotypes. It simultaneously estimates genetic effects on two phenotypes, viability and disease. Simulations show that the v-MFG test produces accurate genetic effect estimates on disease as well as on viability under several different scenarios. It generates accurate type-I error rates and provides adequate power with moderate sample sizes to detect genetic effects on disease risk when viability is reduced. We demonstrate the v-MFG test with HLA-DRB1 data from study participants with rheumatoid arthritis (RA) and their parents, we show that the v-MFG test successfully detects an MFG incompatibility effect on RA while simultaneously adjusting for a possible viability loss.

Developmental vitamin D (DVD) deficiency in the rat alters adult behaviour independently of HPA function

Developmental vitamin D deficiency (DVD) has been shown to alter the orderly pattern of brain development. Even though the period of vitamin D deficiency is restricted to gestation this is sufficient to induce behavioural abnormalities in the adult offspring consistent with those seen in many animal models of schizophrenia. Given that some of these behavioural alterations could also be an indirect result of either impaired maternal hypothalamic pituitary axis (HPA) function (which in turn could influence maternal care) or the result of a permanent alteration in HPA function in the adult offspring we have examined HPA status in both maternal animals and adult offspring. In this study we have established that HPA function is normal in the maternally vitamin D deficient rat. We replicate the behavioural phenotype of hyperlocomotion whilst establishing that HPA function is also unchanged in the adult mate offspring. We conclude that the behavioural alterations induced by DVD deficiency are due to some adverse event in brain development rather than via an alteration in stress response. (c) 2006 Elsevier Ltd. All rights reserved.

Maternal alcohol use disorder and offspring ADHD: disentangling genetic and environmental effects using a children-of-twins design

Background. Children of alcoholics are significantly more likely to experience high-risk environmental exposures, including prenatal substance exposure, and are more likely to exhibit externalizing problems [e.g. attention deficit hyperactivity disorder (ADHD)]. While there is evidence that genetic influences and prenatal nicotine and/or alcohol exposure play separate roles in determining risk of ADHD, little has been done on determining the joint roles that genetic risk associated with maternal alcohol use disorder (AUD) and prenatal risk factors play in determining risk of ADHD. Method. Using a children-of-twins design, diagnostic telephone interview data from high-risk families (female monozygotic and dizygotic twins concordant or discordant for AUD as parents) and control families targeted from a large Australian twin cohort were analyzed using logistic regression models. Results. Offspring of twins with a history of AUD, as well as offspring of non-AUD monozygotic twins whose co-twin had AUD, were significantly more likely to exhibit ADHD than offspring of controls. This pattern is consistent with a genetic explanation for the association between maternal AUD and increased offspring risk of ADHD. Adjustment for prenatal smoking, which remained significantly predictive, did not remove the significant genetic association between maternal AUD and offspring ADHD. Conclusions. While maternal smoking during pregnancy probably contributes to the association between maternal AUD and offspring ADHD risk, the evidence for a significant genetic correlation suggests: (i) pleiotropic genetic effects, with some genes that influence risk of AUD also influencing vulnerability to ADHD; or (ii) ADHD is a direct risk-factor for AUD.

Prenatal diagnosis of tetrasomy 18p using multiplex fluorescent PCR and comparison with a variety of techniques

We report genetic characterization of isochromosome 18p using a combination of cytogenetic and molecular genetic methods, including multiplex fluorescent PCR. The patient was referred for chorionic villus sampling (CVS) due to advanced maternal age and maternal anxiety. The placental karyotype was 47,XX,+mar, with the marker having the appearance of a small supernumerary isochromosome. Because differentiating between isochromosomes and other structural rearrangements is normally very difficult, a variety of genetic tests including fluorescence in situ hybridization (FISH), PCR, and multiplex fluorescent PCR were undertaken to determine chromosomal origin and copy number and, thus, allow accurate diagnosis of the corresponding syndrome. FISH determined that the marker chromosome contained chromosome 18 material. PCR of a variety of short tandem repeats (STRs) confirmed that there was at least one extra copy of the maternal 18p material. However, neither FISH nor PCR could accurately determine copy number. Multiplex fluorescent PCR (MF-PCR) of STRs simultaneously determined that: (1) the marker included 18p material; (2) the marker was maternal in origin; (3) allele copy number indicated tetrasomy; and (4) contamination of the sample could be ruled out. Results were also rapid with accurate diagnosis of the syndrome tetrasomy 18p possible within 5 hours.

An investigation into effects of long-distance seed dispersal on organelle population genetic structure and colonization rate: a model analysis

A simulation-based modelling approach is used to examine the effects of stratified seed dispersal (representing the distribution of the majority of dispersal around the maternal parent and also rare long-distance dispersal) on the genetic structure of maternally inherited genomes and the colonization rate of expanding plant populations. The model is parameterized to approximate postglacial oak colonization in the UK, but is relevant to plant populations that exhibit stratified seed dispersal. The modelling approach considers the colonization of individual plants over a large area (three 500 km x 10 km rolled transects are used to approximate a 500 km x 300 km area). Our approach shows how the interaction of plant population dynamics with stratified dispersal can result in a spatially patchy haplotype structure. We show that while both colonization speeds and the resulting genetic structure are influenced by the characteristics of the dispersal kernel, they are robust to changes in the periodicity of long-distance events, provided the average number of long-distance dispersal events remains constant. We also consider the effects of additional physical and environmental mechanisms on plant colonization. Results show significant changes in genetic structure when the initial colonization of different haplotypes is staggered over time and when a barrier to colonization is introduced. Environmental influences on survivorship and fecundity affect both the genetic structure and the speed of colonization. The importance of these mechanisms in relation to the postglacial spread and genetic structure of oak in the UK is discussed.

Induction and transmission of Bacillus thuringiensis tolerance in the flour moth Ephestia kuehniella

The use of Bacillus thuringiensis (Bt) endotoxins to control insect vectors of human diseases and agricultural pests is threatened by the possible evolution of resistance in major pest species. In addition to high levels of resistance produced by receptor insensitivity (5, 16, 17), several cases of tolerance to low to medium levels of toxin have been reported in laboratory colonies of lepidopteran species (3, 18). Because the molecular basis of some of these cases of tolerance to the toxin are not known, we explored alternative mechanisms. Here, we present evidence that tolerance to a Bt formulation in a laboratory colony of the flour moth Ephestia kuehniella can be induced by preexposure to a low concentration of the Bt formulation and that the tolerance correlates with an elevated immune response. The data also indicate that both immune induction and Bt tolerance can be transmitted to offspring by a maternal effect and that their magnitudes are determined by more than one gene.