Rhesus D Prophylaxis: When and Why We Give Rhesus D Immunoglobulin

Importance

Hemolytic disease of the fetus and newborn (HDFN) is caused by maternal alloantibodies to fetal red blood cells and is associated with significant fetal and neonatal morbidity and mortality. Rhesus D antigen (RhD)-mediated HDFN is the only preventable cause of alloimmunization in pregnancy. Widespread utilization of RhD prophylaxis reduces the risk of RhD-mediated alloimmunization from 17% to <1% in at-risk pregnancies, although RhD-mediated HDFN still occurs.

Objective

To emphasize significance of RhD prophylaxis, outline current guideline-directed indications for administration, provide clarification in areas of uncertainty regarding prophylaxis administration, and review key concepts relevant to patient education and shared decision-making.

Evidence Acquisition

PubMed and Google Scholar literature search.

Results

Data over several decades have shown implementation of prenatal and postpartum RhD prophylaxis has significantly reduced incidence and morbidity of RhD-mediated HDFN. Most international guidelines recommend routine prophylaxis of Rh-negative mothers in the second trimester and peripartum, with additional prophylaxis following certain high-risk events. Recent shortages in RhD immunoglobulin (RhDIg) and new methods to determine fetal blood type have prompted renewed debate regarding criteria for prophylaxis during the first trimester.

Conclusion

Understanding indications for administration of RhD prophylaxis is essential for preventing RhD alloimmunization. Although uncertainty remains in some clinical scenarios, prophylaxis is strongly recommended in Rh-negative mothers in the second trimester, following events high-risk for sensitization in pregnancy, and postpartum.

Relevance

In this review, the etiology of alloimmunization and indications for RhDIg prophylaxis, current society recommendations, and areas of debate are summarized and discussed.

Ejaculate Adjustment in Response to Sperm Competition Risk in Humans

Previous research suggests that human males, like males of many mammalian and avian species, adjust their ejaculate quality in accordance with sperm competition risk. Men who spend less time with their regular female partner since the couple's last copulation produce ejaculates with more sperm at the couple's next copulation (Baker & Bellis, 1993). We conducted a conceptual replication of this research to investigate whether sperm competition risk predicts ejaculate adjustment in human males using additional measures of sperm competition risk (e.g., perceptions of partner infidelity, presence of potential sexual rivals) and updated laser-optic semen analysis technology. We collected data from 34 heterosexual couples (age range 18-32 years) from a university population who completed self-report surveys on their relationship dynamics and provided six ejaculate samples (three copulatory and three masturbatory) across a 45-day period. Time spent together since the couple's last copulation was not significantly associated with ejaculate quality. However, sperm concentration for copulatory ejaculates was higher for men who perceived more potential sexual rivals. Discussion situates the current results within the literature on human sperm competition and suggests several directions for future research.

Uncertainty about paternity: a study on deliberate ignorance

Deliberate ignorance is the willful choice not to know the answer to a question of personal relevance. The question of whether a man is the biological father of his child is a sensitive issue in many cultures and can lead to litigation, divorce, and disinheritance. Thanks to DNA tests, men are easily able to resolve the uncertainty. Psychological theories that picture humans as informavores who are averse to ambiguity suggest men would do a DNA test, as does evolutionary theory, which considers investing in raising a rival's offspring a mistake. We conducted two representative studies using computer-based face-to-face interviews in Germany (n = 969) and Spain (n = 1,002) to investigate whether men actually want to know and how women would react to this desire. As a base line, Germans (Spanish) estimated that 10% (20%) of fathers mistakenly believe that they are the biological father of their child. Nevertheless, in both countries, only 4% of fathers reported that they had performed a DNA paternity test, while 96% said they had not. In contrast, among men without children, 38% (33%) of Germans (Spanish) stated they would do a DNA test if they had children, mostly without telling their partners. Spanish women with children would more often disapprove of a paternity test or threaten their husbands with divorce (25%) than would German women (13%). We find that a simple test of risk aversion, measured also by the purchase of non-mandatory insurances, is correlated with not wanting to know.

Mate Retention Behavior and Ejaculate Quality in Humans

Males of some species use mate retention behavior and investment in ejaculate quality as anti-cuckoldry tactics concurrently while others do so in a compensatory fashion. Leivers, Rhodes, and Simmons (2014) reported that men who performed mate retention less frequently produced higher-quality ejaculates, suggesting that humans use these tactics compensatorily. We conducted a conceptual replication of this research in a sample of 41 men (18-33 years; M = 23.33; SD = 3.60). By self-report, participants had not had a vasectomy and had never sought infertility treatment. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationships between mate retention behavior and four components of ejaculate quality: sperm velocity, sperm concentration, slow motility, and ejaculate volume. The present results provide little support for the hypothesis that human males deploy mate retention behavior and ejaculate quality investment compensatorily. We discuss the limitations of this study and highlight the need for research to address questions about the nature of anti-cuckoldry tactic deployment in humans, especially concerning investment in ejaculate quality.

The role of balancing selection in maintaining human RhD blood group polymorphism: A preregistered cross-sectional study

Maintenance of genetic polymorphism remains one of the big questions of evolutionary biology, which for a long time tended to be explained by balancing selection. This explanation was later criticized, but now is again accepted as an important mechanism in evolution. Human blood group systems seem affected by balancing selection especially strongly. In this preregistered study, we focused on stable coexistence of RhD-positive and RhD-negative subjects in a population. This is an evolutionary conundrum, because carriers of the less frequent negative allele suffer from lower fecundity due to haemolytic disease of the newborn affecting RhD-positive infants born to RhD-negative women. One explanation of persisting stability of RhD polymorphism points to heterozygote advantage. Over the past decade, numerous studies demonstrated that RhD-positive subjects score better than RhD-negative homozygotes in psychomotor tests and physical health-related variables. Still, evidence of better health and performance of heterozygotes is scarce and merely indirect. We compared the physical and mental health of 2,539 subjects whose RhD genotype was estimated based on their and their parents' RhD phenotype. We confirmed that RhD-negative homozygotes fare worse in terms of physical and mental health than subjects with RhD-positive phenotype and that RhD-positive heterozygotes enjoy better health than both homozygotes. For the first time, we demonstrated that RhD-positive homozygotes might suffer from worse health than RhD-negative homozygotes. Our results strongly support the hypothesis that RhD polymorphism is maintained by heterozygote advantage and that balancing selection may have played an important role in human evolution in this context and in general.

Type of paternal sperm exposure before pregnancy and the risk of preeclampsia: A systematic review

OBJECTIVE

The aim of this systematic review was to evaluate the role of paternal sperm exposure before pregnancy on the risk of preeclampsia.

STUDY DESIGN

The search was conducted using electronic databases from inception of each database through October 2019. Review of articles also included the abstracts of all references retrieved from the search. Only studies evaluating exposure to paternal sperm before pregnancy on the risk of preeclampsia in the subsequent pregnancy were included. Exposure group was defined as significant exposure to paternal sperm, either measured by sexual cohabitation, oral sex habit, or by absence of barrier methods. Control groups was defined as minimal exposure to paternal sperm, either measured by lack of sexual cohabitation or oral sex habit, or by use of barrier methods. Sperm exposure identifiable before pregnancy that may be suspected to modify the risk of preeclampsia was examined. The primary outcome was the incidence of preeclampsia. Subgroup analyses by parity and type of sperm exposure were planned. All analyses were carried out using the random effects model. The pooled results were reported as the OR with 95 % confidence interval (CI). Heterogeneity was measured using I-squared (Higgins I2).

RESULTS

Seven studies including 7125 pregnant women were included in this systematic review. Overall, the incidence of preeclampsia was similar in women with a higher overall sperm exposure compared to controls, 774/5512 (14 %) vs 220/1619 (13.6 %); OR 1.04, 95 % CI 0.88-1.22, respectively. The incidence of preeclampsia was significantly reduced in women with a higher overall sperm exposure when including only nulliparous women, 643/3946 (16.1 %) vs 170/725 (23.4 %); OR 0.63, 95 % CI 0.52 to 0.76. Significant lower rate of preeclampsia was also found for ≥12-month sexual cohabitation, 494/3627 (13.6 %) vs 123/691 (17.8 %); OR 0.73, 95 % CI 0.59-0.90. Significantly higher rate of preeclampsia was reported in women not using barrier methods, 315/1904 (16.5 %) vs 103/962 (10.7 %); OR 1.65, 95 % CI 1.30-2.10.

CONCLUSIONS

Paternal sperm exposure in nulliparous women and sexual cohabitation > 12 months before pregnancy are associated with a decreased risk of preeclampsia.

Considerations for whole exome sequencing unique to prenatal care

Whole exome sequencing (WES) is increasingly being used in the prenatal setting. The emerging data support the clinical utility of prenatal WES based on its diagnostic yield, which can be as high as 80% for certain ultrasound findings. However, detailed practice and laboratory guidelines, addressing the indications for prenatal WES and the surrounding technical, interpretation, ethical, and counseling issues, are still lacking. Herein, we review the literature and summarize the most recent findings and applications of prenatal WES. This review offers specialists and clinical genetic laboratorians a body of evidence and expert opinions that can serve as a resource to assist in their practice. Finally, we highlight the emerging technologies that promise a future of prenatal WES without the risks associated with invasive testing.

Cell free fetal DNA to triage antenatal rhesus immune globulin: Is it really cost-effective in the United States?

OBJECTIVE

To compare the efficacy and costs of three different strategies of antenatal rhesus immune globulin (RhIG) administration in a US population.

METHODS

A decision tree analysis was undertaken for universal antenatal RhIG administration based on RhD serologic paternity testing, universal administration without paternity, and selective antenatal RhIG administration using cell free fetal DNA (cfDNA) for RHD fetal typing. Rates of alloimmunization were calculated. Charges were determined for laboratory testing and obstetrical and neonatal treatments for the first pregnancy and cases of alloimmunization in the following pregnancy.

RESULTS

The largest number of new RhD alloimmunization cases resulted from a strategy of universal RhIG that included paternity. Fewer cases resulted from a selective strategy; the least number of cases were associated with a universal approach that discounted paternity. When the costs of first pregnancies and alloimmunized second pregnancies were combined, a universal strategy that excludes paternity had the least costs followed by a selective strategy followed by a universal strategy that included paternity.

CONCLUSION

The use of cfDNA to determine the selective use of antenatal RhIG would not be cost-effective in the United States. Universal antenatal RhIG without paternity is more effective in preventing new cases of alloimmunization than the current ACOG guideline.

Do mothers also "manipulate" grandparental care?

Paternity uncertainty has proven to be a robust ultimate hypothesis for predicting the higher investment in grandchildren observed among maternal grandparents compared to that of the paternal grandparents. Yet the proximate mechanisms for generating such preferred biases in grandparental investment remain unclear. Here we address two different questions for better understanding the proximate mechanisms leading to the observed bias in grandparental investments: (i) is there a larger emphasis on resemblance descriptions (between grandchildren and grandparent) among daughters than among sons, and (ii) do mothers really believe that their offspring more resemble their parents, that is, the children's grandparents, than fathers do? From questioning grandparents, we find that daughters more often and more intensely than sons express opinions about grandchild-grandparent resemblance. Moreover, daughters also seem to believe that their children more resemble their grandmother than sons do. The latter is, however, not the case for beliefs about children's resemblance to grandfathers. In sum, our results suggest that even in a population of Norwegians, strongly influenced by ideas concerning gender equality, there exist a sexual bias among parents in opinions and descriptions about grandchild-grandparent resemblance. This resemblance bias, which echoes that of mothers biasing resemblance descriptions of newborns to putative fathers, does not seem to represent a conscious manipulation. Yet it could be instrumental for influencing grandparental investments. We believe that a "manipulative mother hypothesis" might parsimoniously account for many of the results relating to biased alloparenting hitherto not entirely explained by "the paternity uncertainty hypothesis."

Mate Preferences and Their Behavioral Manifestations

Evolved mate preferences comprise a central causal process in Darwin's theory of sexual selection. Their powerful influences have been documented in all sexually reproducing species, including in sexual strategies in humans. This article reviews the science of human mate preferences and their myriad behavioral manifestations. We discuss sex differences and sex similarities in human sexual psychology, which vary according to short-term and long-term mating contexts. We review context-specific shifts in mating strategy depending on individual, social, and ecological qualities such as mate value, life history strategy, sex ratio, gender economic inequality, and cultural norms. We review the empirical evidence for the impact of mate preferences on actual mating decisions. Mate preferences also dramatically influence tactics of mate attraction, tactics of mate retention, patterns of deception, causes of sexual regret, attraction to cues to sexual exploitability, attraction to cues to fertility, attraction to cues to resources and protection, derogation of competitors, causes of breakups, and patterns of remarriage. We conclude by articulating unresolved issues and offer a future agenda for the science of human mating, including how humans invent novel cultural technologies to better implement ancient sexual strategies and how cultural evolution may be dramatically influencing our evolved mating psychology.

Do Men Produce Higher Quality Ejaculates When Primed With Thoughts of Partner Infidelity?

Sperm competition theory can be used to generate the hypothesis that men alter the quality of their ejaculates as a function of sperm competition risk. Using a repeated measures experimental design, we investigated whether men produce a higher quality ejaculate when primed with cues to sperm competition (i.e., imagined partner infidelity) relative to a control prime. Men ( n = 45) submitted two masturbatory ejaculates-one ejaculate sample for each condition (i.e., sperm competition and control conditions). Ejaculates were assessed on 17 clinical parameters. The results did not support the hypothesis: Men did not produce higher quality ejaculates in the sperm competition condition relative to the control condition. Despite the null results of the current research, there is evidence for psychological and physiological adaptations to sperm competition in humans. We discuss methodological limitations that may have produced the null results and present methodological suggestions for research on human sperm competition.

Familial Resemblance in Dietary Intakes of Children, Adolescents, and Parents: Does Dietary Quality Play a Role?

Information on familial resemblance is important for the design of effective family-based interventions. We aimed to quantify familial correlations and estimate the proportion of variation attributable to genetic and shared environmental effects (i.e., familiality) for dietary intake variables and determine whether they vary by generation, sex, dietary quality, or by the age of the children. The study sample consisted of 1435 families (1007 mothers, 438 fathers, 1035 daughters, and 1080 sons) from the multi-center I.Family study. Dietary intake was assessed in parents and their 2–19 years old children using repeated 24-h dietary recalls, from which the usual energy and food intakes were estimated with the U.S. National Cancer Institute Method. Food items were categorized as healthy or unhealthy based on their sugar, fat, and fiber content. Interclass and intraclass correlations were calculated for relative pairs. Familiality was estimated using variance component methods. Parent–offspring (r = 0.11–0.33), sibling (r = 0.21–0.43), and spouse (r = 0.15–0.33) correlations were modest. Parent–offspring correlations were stronger for the intake of healthy (r = 0.33) than unhealthy (r = 0.10) foods. Familiality estimates were 61% (95% CI: 54–68%) for the intake of fruit and vegetables and the sum of healthy foods and only 30% (95% CI: 23–38%) for the sum of unhealthy foods. Familial factors explained a larger proportion of the variance in healthy food intake (71%; 95% CI: 62–81%) in younger children below the age of 11 than in older children equal or above the age of 11 (48%; 95% CI: 38–58%). Factors shared by family members such as genetics and/or the shared home environment play a stronger role in shaping children’s intake of healthy foods than unhealthy foods. This suggests that family-based interventions are likely to have greater effects when targeting healthy food choices and families with younger children, and that other sorts of intervention are needed to address the intake of unhealthy foods by children.

Genetic-genealogy approach reveals low rate of extrapair paternity in historical Dutch populations

OBJECTIVE

Evolutionary theory has shown that seeking out extrapair paternity (EPP) can be a viable reproductive strategy for both sexes in pair-bonded species, also in humans. As yet, estimates of the contemporary or historical EPP rate in human population are still rare. In the present study, we estimated the historical EPP rate in the Dutch population over the last 400 years and compared the rate with those obtained for other human populations to determine the evolutionary, cultural, and socio-demographic factors that influence human cuckoldry behavior.

METHODS

We estimated the historical EPP rate for the Dutch population via the "genealogical pair method", in which the EPP rate is derived from Y-chromosome mismatches between pairs of individuals that, based on genealogical evidence, share a common paternal ancestor.

RESULTS

Based on the analysis of 68 representative genealogical pairs, separated by a total of 1013 fertilization events, we estimated that the historical EPP rate for the Dutch population over the last 400 years was 0.96% per generation (95% confidence interval 0.46%-1.76%).

CONCLUSION

The Dutch EPP rate fits perfectly within the range reported for other contemporary and historical populations in Western Europe and was highly congruent with that estimated for neighboring Flanders, despite the socio-economic and religious differences between both populations. The estimated low EPP rate challenges the "dual mating strategy hypothesis" that states that women could obtain fitness benefits by securing investment from one man while cuckolding him to obtain good genes from an affair partner.

Cuckolded Fathers Rare in Human Populations

Contemporary data of extra-pair paternity (EPP) in human populations may be biased by the use of modern contraceptives. Studies have now estimated historical EPP rates in several human populations. The observed low EPP rates challenge the idea that women routinely 'shop around' for good genes by engaging in extra-pair copulations.

Sperm Competition Risk and Sexual Coercion Predict Copulatory Duration in Humans

A man whose romantic partner is sexually unfaithful is at risk of sperm competition and cuckoldry-unwitting investment in offspring to whom he is genetically unrelated. Men, therefore, may have evolved mechanisms to solve the adaptive problems of sperm competition and cuckoldry. The current research investigates another potential anti-cuckoldry tactic: reducing in-pair copulation (IPC) duration, thereby more quickly placing his sperm into competition. We hypothesize that IPC duration will be negatively correlated with female infidelity (Hypothesis 1). We further hypothesize that IPC duration will be negatively correlated with sexual coercion (Hypothesis 2). Results of Study 1 (men's reports, n = 410) indicate that both men's perceptions of female infidelity and men's sexual coercion predict shorter IPC duration. Results of Study 2 (women's reports, n = 455) did not provide statistical support for the study hypotheses. The current research provides an initial investigation of men's adjustment of copulatory duration and suggests that men reduce IPC duration and ejaculate more quickly at the couple's most recent copulation, in response to greater risk of sperm competition and in the context of sexual coercion.

Three hundred years of low non-paternity in a human population

When cuckoldry is frequent we can expect fathers to withhold investment in offspring that may not be theirs. Human paternal investment can be substantial and is in line with observations from tens of thousands of conceptions that suggest that cuckoldry is rare in humans. The generality of this claim seems to be in question as the rate of cuckoldry varies across populations and studies have mostly been on Western populations. Two additional factors complicate our conclusions, (1) current estimates of the rate of cuckoldry in humans may not reflect our past behaviour as adultery can be concealed by the use of contraceptives; and (2) it is difficult to obtain samples that are random with respect to their paternity certainty. Studies that combine genealogies with Y-chromosome haplotyping are able to circumvent some of these problems by probing into humans' historical behaviour. Here we use this approach to investigate 1273 conceptions over a period of 330 years in 23 families of the Afrikaner population in South Africa. We use haplotype frequency and diversity and coalescent simulations to show that the male population did not undergo a severe bottleneck and that paternity exclusion rates are high for this population. The rate of cuckoldry in this Western population was 0.9% (95% confidence interval 0.4-1.5%), and we argue that given the current data on historical populations we have to conclude that, at least for Western human populations, cuckoldry rate is probably in the range of 1%.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal “head and trunk skeletal size,” “adiposity,” and “limb lengths.” Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. Am J Phys Anthropol 156:625–636, 2015.

Trends in parent-child correlations of childhood body mass index during the development of the obesity epidemic

Background

The intergenerational resemblance in body mass index may have increased during the development of the obesity epidemic due to changes in environment and/or expression of genetic predisposition.

Objectives

This study investigates trends in intergenerational correlations of childhood body mass index (BMI; kg/m²) during the emergence of the obesity epidemic.

Methods

The study population was derived from the Copenhagen School Health Records Register, which includes height and weight measurements since birth year 1930. Mothers and fathers with BMIs available at ages 7 (n = 25,923 and n = 20,972) or 13 years (n = 26,750 and n = 21,397), respectively, were linked through the civil registration system introduced in 1968 to their children with BMIs available at age 7 years. Age- and sex-specific BMI z-scores were calculated. Correlations were estimated across eight intervals of child birth years (1952–1989) separately by sex. Trends in these correlations were examined. Whereas the mother-child correlations reflected the biological relationship, a likely decline in the assignment of non-biological fathers through the registration system across time must be considered when interpreting the father-child correlations.

Results

The BMI correlations between mothers and sons ranged from 0.29–0.36 and they decreased marginally, albeit significantly across time at ages 7–7 years (−0.002/year, p = 0.006), whereas those at 13–7 years remained stable (<0.0004/year, p = 0.96). Mother-daughter correlations ranged from 0.30–0.34, and they were stable at ages 7–7 years (0.0001/year, p = 0.84) and at 13–7 years (0.0004/year, p = 0.56). In contrast, father-son correlations increased significantly during this period, both at ages 7–7 (0.002/year, p = 0.007) and at ages 13–7 years (0.003/year, p<0.001), whereas the increase in father-daughter correlations were insignificant both at ages 7–7 (0.001/year, p = 0.37) and at ages 13–7 years (0.001/year, p = 0.18).

Conclusion

During the obesity epidemics development, the intergenerational resemblance with mothers remained stable, whereas the father-child BMI resemblance increased, possibly reflecting changes in family relationships, and unlikely to have influenced the epidemic.

Birth outcomes of pregnancies fathered by men with multiple sclerosis

We linked several population-based clinical and health administrative databases in British Columbia, Canada. We identified and compared birth outcomes of pregnancies fathered by men with multiple sclerosis (MS) (n=202) and men from a frequency-matched general population cohort (n=981) between 1996 and 2010. Using multivariate models, we analyzed the association of paternal MS, disease duration at conception and disability (as measured by the Expanded Disability Status Scale) with birth weight and gestational age. Paternal MS and MS-related clinical factors were not significantly associated with birth outcomes (p>0.05). This study provides assurance to expecting fathers with MS and their families.

Low historical rates of cuckoldry in a Western European human population traced by Y-chromosome and genealogical data

Recent evidence suggests that seeking out extra-pair paternity (EPP) can be a viable alternative reproductive strategy for both males and females in many pair-bonded species, including humans. Accurate data on EPP rates in humans, however, are scant and mostly restricted to extant populations. Here, we provide the first large-scale, unbiased genetic study of historical EPP rates in a Western European human population based on combining Y-chromosomal data to infer genetic patrilineages with genealogical and surname data, which reflect known historical presumed paternity. Using two independent methods, we estimate that over the last few centuries, EPP rates in Flanders (Belgium) were only around 1–2% per generation. This figure is substantially lower than the 8–30% per generation reported in some behavioural studies on historical EPP rates, but comparable with the rates reported by other genetic studies of contemporary Western European populations. These results suggest that human EPP rates have not changed substantially during the last 400 years in Flanders and imply that legal genealogies rarely differ from the biological ones. This result has significant implications for a diverse set of fields, including human population genetics, historical demography, forensic science and human sociobiology.

Genetic genealogy reveals true Y haplogroup of House of Bourbon contradicting recent identification of the presumed remains of two French Kings

Genetic analysis strongly increases the opportunity to identify skeletal remains or other biological samples from historical figures. However, validation of this identification is essential and should be done by DNA typing of living relatives. Based on the similarity of a limited set of Y-STRs, a blood sample and a head were recently identified as those belonging respectively to King Louis XVI and his paternal ancestor King Henry IV. Here, we collected DNA samples from three living males of the House of Bourbon to validate the since then controversial identification of these remains. The three living relatives revealed the Bourbon's Y-chromosomal variant on a high phylogenetic resolution for several members of the lineage between Henry IV and Louis XVI. This 'true' Bourbon's variant is different from the published Y-STR profiles of the blood as well as of the head. The earlier identifications of these samples can therefore not be validated. Moreover, matrilineal genealogical data revealed that the published mtDNA sequence of the head was also different from the one of a series of relatives. This therefore leads to the conclusion that the analyzed samples were not from the French kings. Our study once again demonstrated that in order to realize an accurate genetic identification of historical remains DNA typing of living persons, who are paternally or maternally related with the presumed donor of the samples, is required.

Adolescent grandchildren's perceptions of grandparents' involvement in UK: an interpretation from life course and evolutionary theory perspective

In this article, we study grandparental involvement from the viewpoint of evolutionary theory and sociological life course perception. We have used 'the Involved Grandparenting and Child Well-Being 2007' survey, which is the first nationally representative sample of British and Welsh adolescents aged 11-16 (n = 1,488). First, we explore with the descriptive statistics the amount of grandparental involvement reported by adolescents. The result follows the predicted pattern: maternal grandparent is reported to involve in a grandchild's life the most, second maternal grandfather, third paternal grandmother and the last paternal grandfather. Second, we focus more closely on separate grandparents and show with four linear regression models which factors are connected to each grandparent's involvement. Grandchild's age, grandparent's health, grandparent's labour force participation and distance between a grandparent and a grandchild were factors that have similar effects in relation to all grandparents. Marital status mattered only for grandfathers, whereas family structure of a grandchild has opposite effects in relation to maternal and paternal grandparents. Grandchild's sex, grandparent's age, the number of grandchildren and the number of living grandparents all mattered, but only with respect to some grandparents. The study shows that it is advantageous to merge sociological and evolutionary viewpoints when studying a grandparental involvement in a modern society.

Detection of uniparental isodisomy in autosomal recessive mitochondrial DNA depletion syndrome by high-density SNP array analysis

Mitochondrial DNA (mtDNA) depletion syndrome encompasses a heterogeneous group of disorders characterized by a reduction in the mtDNA copy number. We identified two patients with clinical presentations consistent with mtDNA depletion syndrome (MDS), who were subsequently found to have apparently homozygous point mutations in TYMP and DGUOK, two of the nine nuclear genes commonly associated with these disorders. Further sequence analyses of parents indicated that in each case only one parent; the mother of the first and the father of the second, was a heterozygous carrier of the mutation identified in the affected child. The presence of underlying deletions was ruled out by use of a custom target array comparative genomic hybridization (CGH) platform. A high-density single-nucleotide polymorphism (SNP) array analysis revealed that the first patient had a region of copy-neutral absence of heterozygosity (AOH) consistent with segmental isodisomy for an 11.3 Mb region at the long-arm terminus of chromosome 22 (including the TYMP gene), and the second patient had results consistent with complete isodisomy of chromosome 2 (where the DGUOK gene is located). The combined sequencing, array CGH and SNP array approaches have demonstrated the first cases of MDS due to uniparental isodisomy. This diagnostic scenario also demonstrates the necessity of comprehensive examination of the underlying molecular defects of an apparently homozygous mutation in order to provide patients and their families with the most accurate molecular diagnosis and genetic counseling.

Grandparental child care in Europe: evidence for preferential investment in more certain kin

Theories of kin selection and parental investment predict stronger investment in children and grandchildren by women and maternal kin. Due to paternity uncertainty, parental and grandparental investments along paternal lineages are based on less certain genetic relatedness with the children and grandchildren. Additionally, the hypothesis of preferential investment (Laham, Gonsalkorale, and von Hippel, 2005) predicts investment to vary according to available investment options. Two previous studies have tested this hypothesis with small samples and conflicting results. Using the second wave of the large and multinational Survey of Health, Ageing and Retirement in Europe (SHARE), collected in 2006-07, we study the preferential investment hypothesis in contemporary Europe based on self-reported grandparental provision of child care. We predict that 1) maternal grandmothers provide most care for their grandchildren, followed by maternal grandfathers, paternal grandmothers and last by paternal grandfathers; 2) maternal grandfathers and paternal grandmothers provide equal amounts of care when the latter do not have grandchildren via a daughter; 3) women who have grandchildren via both a daughter and a son will look after the children of the daughter more; and 4) men who have grandchildren via both a daughter and a son will look after the children of the daughter more. Results support all four hypotheses and provide evidence for the continuing effects of paternity uncertainty in contemporary kin behavior.

The Future of an Applied Evolutionary Psychology for Human Partnerships

There has been significant recent progress in our understanding of human mate choice. We outline several frontiers of rapid cultural change which may increasingly directly affect individual self-evaluation in the mating market, formation and maintenance of long-term partnerships, and potentially reproductive outcome and child health. Specifically, we review evidence for the effects of (1) increasing exposure to mass media, (2) the advent of novel ways to meet potential partners, and (3) cultural influences which may disrupt or alter the expression of evolved mate preferences. We comment on the potential for these effects to influence self-perception and partner-perception, with downstream effects on relationship satisfaction and stability. A common theme emerges, which is that these effects may contribute to relationship dissatisfaction and dissolution, with negative implications for societal change. We then address how we envisage evolutionary psychology research may focus on and offer informed approaches to ameliorate these effects in the future. We picture the development of a field of applied evolutionary psychology, and we suggest that this will increasingly become a central focus for many researchers.

Comparing maternal and paternal intergenerational transmission of obesity risk in a large population-based sample

BACKGROUND

Previous research showed childhood obesity to be more strongly associated with maternal weight than with paternal weight. However, confidence in this finding is limited by the lack of objectively measured data from both parents.

OBJECTIVE

We quantified the individual and combined effects of maternal and paternal overweight/obesity on obesity risk in children.

DESIGN

Data were pooled from the annual Health Surveys for England carried out between 2001 and 2006. Families with < or =2 children aged 2-15 y with anthropometric data available for both parents and children were included (n = 4432 families, n = 7078 children). Weights and heights were measured by a trained nurse.

RESULTS

Having 2 overweight parents was associated with an increased risk of child obesity [odds ratio (OR): 2.2; 95% CI: 1.3, 3.7; P < 0.001] compared with having 2 normal-weight parents. Having 2 obese (including severely obese) parents was associated with a higher risk of child obesity (OR: 12.0; 95% CI: 7.2, 20.1; P < 0.01), and having 2 severely obese parents was associated with an even higher risk of child obesity (OR: 22.3; 95% CI: 10.3, 48.4; P < 0.01) independent of age, sex, socioeconomic status, and ethnicity. Mother-child associations (r = 0.27) for body mass index were significantly stronger than father-child associations (r = 0.23), even after adjustment for plausible levels (< or =4%) of undisclosed nonpaternity. Associations were the same for sons and daughters but increased with age.

CONCLUSIONS

There is a strong and graded association between parental weight status and risk of childhood obesity, which is significantly stronger for maternal weight. Parental obesity could be used to target preventive interventions in the preschool years to avoid serious adverse effects on the future health of children.