On some novel aspects of consanguineous marriages

Awareness of consanguineous marriage burden and willingness towards premarital genetic testing in Sudan: a national cross-sectional study

Background

Despite the widespread practice of consanguinity in Sudan, there is a lack of exploration into the community's awareness of its health implications on offspring and their overall attitude towards consanguineous unions.

Aim

This study aimed to evaluate the community's awareness of the possible health adversities of consanguinity on children and assess the effect of knowledge level on the prevailing attitude towards this practice in Sudan.

Methods

From August to December 2018, data were collected from adults aged 18 years and above in five provinces of Sudan regardless of their marital status. The analysis involved both descriptive and multivariate statistical techniques.

Results

This study revealed a consanguinity rate of 30.2%. Despite a high awareness level (73.7%) regarding the effects of consanguineous marriage on the health of the offspring, a moderately negative attitude towards this practice (63.9%) was observed.

Conclusion

The discordance between the high consanguinity rate in the Sudanese population and the moderately negative attitude suggests a potential persistence of this practice in the future. Without the implementation of educational programs and the provision of genetic counselling services to consanguineous couples, the prevalence of consanguinity is likely to endure.

Ancestral reconstruction and correlation of the frequencies of the hemoglobin S allele and the Duffy blood group alleles in human populations

OBJECTIVES

Malaria is an important selective force for human genetic adaptation due to the sustained, lethal impact it has had on populations worldwide. High frequencies of both hemoglobin S and the null allele FYB^ES of the Duffy blood group have been found in areas where this disease is endemic, attributed to the protective action of the carriers of these variants against malaria infection. The objective of this work was to perform ancestral reconstruction and analyze the correlation of the frequencies of these alleles throughout the phylogeny of 24 human populations.

METHODS

A tree topology and the allelic frequencies reported in the literature for the 24 populations were used. The ancestral frequencies for the two alleles were reconstructed using the maximum likelihood method and the Brownian model of evolution (CI = 95%), and the correlation analysis was performed using phylogenetically independent contrasts (PICs). Statistical analyses were performed with the statistical software R version 3.4.1.

RESULTS

For both alleles, a correspondence was found in the reconstruction of the ancestral frequencies, and a significant statistical correlation (p = .001) was observed between the S and FYB^ES alleles.

CONCLUSIONS

These results provide evidence of an epistatic relationship between the two alleles, which may influence the fitness of the individuals who present with them when they are subjected to a selective force such as malaria.

Altruism as an Explanation for Human Consanguinity

BACKGROUND

Human inbreeding is a sociobiological puzzle. Despite widespread knowledge of its potential for genetic disorders, human consanguinity remains surprisingly common. The current reasons explaining its continued persistence in today's modern world have major shortcomings.

SUMMARY

We propose that the Neolithic Agrarian revolution modified the structure of populations. It increased competition for the limited resources in which a larger group had better chances of survival. As a result, small, drifting, socially open bands of hunter-gatherers were transformed into bigger, less mobile, and more powerful kinship groups (tribes). In this transformation, a central role was played by human trust - an aspect of human altruism which is a universal sociobiological principle of behavior. Altruism (and trust) is an essential premise of social contracts such as economic cooperation, marriage arrangement, and creation of alliances between people. In kinship groups, human trust is limited to kin, so tribes remain small, economically poor, and consanguineous due to lack of nonkin mates. The expanding of trust from kin to that of nonbiological relatives increases the size of human groups, fosters economic wealth, and decreases the rate of consanguinity. Key Messages: The lack of nonkin altruism leads to: (a) poverty (due to poor economic cooperation with nonkin), (b) maintaining small group size, and (c) inbreeding.

Consanguineous marriage and its relevance to divorce, polygyny and survival of marriage: evidence from a population-based analysis in Jordan

BACKGROUND

Consanguinity has been extensively studied in the context of its negative health outcomes for offspring and socio-demographic factors, but little evidence-based research has been done on its potential social benefits.

AIM

To examine the association between consanguineous marriage and the risk of divorce or separation, polygyny, and survival of marriage in Jordan.

SUBJECTS AND METHODS

Data were obtained from the 2018 Jordan Population and Family Health Survey, covering a nationally representative sample of ever-married women of reproductive age. Descriptive statistics, multiple logistic regression, and survival analysis techniques were used for data analysis.

RESULTS

The prevalence of consanguineous marriage was found to be 27.5% in Jordan in 2018, while the prevalences of polygyny and divorced/separated rates were 4.4% and 4.7%, respectively. Both consanguineous and polygyny rates showed declining trends, but divorce/separation rate showed an increasing trend. Compared to non-consanguineous marriages, the risk of divorce/separation and polygyny were found to be lower among women with consanguineous marriage, while the survival of marriages was found to be higher for consanguineous marriages than for non-consanguineous marriages.

CONCLUSIONS

Findings revealed that consanguinity has some social benefits as it plays protective roles against divorce or separation, polygyny and enhances the survival of marriages.

Determinación de endogamia mediante método de isonimia en la población de Runta, Boyacá, Colombia

Introducción. Dado el hallazgo de enfermedades raras de herencia recesiva en un número mayor de pacientes al esperado, estudios recientes han sugerido la presencia de un aislado poblacional en la vereda de Runta, en el departamento de Boyacá, Colombia. Esto indica la probabilidad de una tasa de consanguinidad aumentada en dicha población.Objetivos. Determinar los parámetros de endogamia mediante isonimia para analizar la estructura poblacional de la vereda Runta y ayudar a elucidar las causas de la aparición de estas enfermedades.Materiales y métodos. Se establecieron seis parámetros indicativos de estructura poblacional basados en los apellidos registrados en la base de datos del Sistema de Identificación y Selección de Potenciales Beneficiarios de Programas Sociales de los habitantes de Runta.Resultados. Se obtuvo coeficiente de endogamia (θii) de 0.0083, alfa de Fisher (α) de 30.0447 y estimativos A, B y C de 0.0379, 0.3413 y 0.4669, respectivamente. La mayoría de los individuos se encontraron agrupados en los apellidos más frecuentes de la población. Los parámetros de isonimia en Runta son similares a los de comunidades aisladas descritas en la literatura.Conclusión. Los resultados soportan la hipótesis previa de que se está ante un aislado genético en una población muy cercana a la capital del departamento de Boyacá.

CONSANGUINITY BY RANDOM ISONYMY AND SOCIOECONOMIC DEVELOPMENT IN ARGENTINA: A POPULATION STUDY

In human populations various flexible, labile and interdependent structures (genetic, demographic, socioeconomic) co-exist, each of which can be organized in an hierarchical order corresponding to administrative entities. The relationship between consanguinity, as estimated by random isonymy (F ST), and socioeconomic conditions was analysed at different levels of political and administrative organization in Argentina. From the surnames of 22,666,139 voters from the 2001 electoral roll, F ST was estimated for 510 Argentinian departments. Using a principal component analysis, a Socio-Demographic and Economic Indicator (SDEI), summarizing the effect of 22 socioeconomic and demographic variables at the departmental level, was computed. The relationship between departmental F ST and SDEI values was analysed for the whole nation and within regions using multiple regression analysis. The F ST presented a clinal distribution with the highest values in the north and west of the country, while SDEI expressed the opposite behaviour. A negative and significant correlation was observed between F ST and SDEI, accounting for 46% of the variation in consanguinity in Argentina. The strongest correlations of F ST with SDEI were observed in the Central, Patagonia and Cuyo regions, i.e. those with the highest values of SDEI and lowest values of F ST.

Random inbreeding, isonymy, and population isolates in Argentina

Population isolates are an important tool in identifying and mapping genes of Mendelian diseases and complex traits. The geographical identification of isolates represents a priority from a genetic and health care standpoint. The purpose of this study is to analyze the spatial distribution of consanguinity by random isonymy (F ST) in Argentina and its relationship with the isolates previously identified in the country. F ST was estimated from the surname distribution of 22.6 million electors registered for the year 2001 in the 24 provinces, 5 geographical regions, and 510 departments of the country. Statistically significant spatial clustering of F ST was determined using the SaTScan V5.1 software. F ST exhibited a marked regional and departamental variation, showing the highest values towards the North and West of Argentina. The clusters of high consanguinity by random isonymy followed the same distribution. Recognized Argentinean genetic isolates are mainly localized at the north of the country, in clusters of high inbreeding. Given the availability of listings of surnames in high-capacity storage devices for different countries, estimating F ST from them can provide information on inbreeding for all levels of administrative subdivisions, to be used as a demographic variable for the identification of isolates within the country for public health purposes.

Pairomics, the omics way to mate choice

The core aspects of the biology and evolution of sexual reproduction are reviewed with a focus on the diploid, sexually reproducing, outbreeding, polymorphic, unspecialized, altricial and cultural human species. Human mate choice and pair bonding are viewed as central to individuals' lives and to the evolution of the species, and genetic assistance in reproduction is viewed as a universal human right. Pairomics is defined as an emerging branch of the omics science devoted to the study of mate choice at the genomic level and its consequences for present and future generations. In pairomics, comprehensive genetic information of individual genomes is stored in a database. Computational tools are employed to analyze the mating schemes and rules that govern mating among the members of the database. Mating models and algorithms simulate the outcomes of mating any given genome with each of a number of genomes represented in the database. The analyses and simulations may help to understand mating schemes and their outcomes, and also contribute a new cue to the multicued schemes of mate choice. The scientific, medical, evolutionary, ethical, legal and social implications of pairomics are far reaching. The use of genetic information as a search tool in mate choice may influence our health, lifestyle, behavior and culture. As knowledge on genomics, population genetics and gene-environment interactions, as well as the size of genomic databases expand, so does the ability of pairomics to investigate and predict the consequences of mate choice for the present and future generations.