Prevalence of consanguineous marriages in west and south of Afghanistan

Analyzing Inbreeding and Estimating Its Related Deficiencies in Northeastern Brazil

This cross-sectional study aimed to observe number of marriages between relatives in São Francisco Valley municipalities and correlations between degrees of kinship and susceptibility to genetic diseases. Three hundred and nine (309) consanguineous couples were interviewed in five municipalities. The data were analyzed using SPSS (version 22), Chi-square testing, and the generalized estimating equation (GEE). In Pariconha-AL for first cousins, the results revealed significantly higher numbers of disabled children than for third cousins (p < 0.05). Of these, the prevalence for physical disability was significant (χ2 = 19.203, df = 4, p = 0.001). In the cities of Glória-BA (χ2 = 11.652, df = 3, p = 0.020) and OlhoD'água do Casado-AL (χ2 = 8.123, df = 4, p = 0.044), physical disabilities were also significantly higher in children from unions of first-degree cousins than for other degrees of kinship. Visual impairment was more significant in first-degree cousins in Glória-BA (χ2 = 14.206, df = 3 p = 0.007); yet among third-degree cousins, visual impairment in the municipality of Santa Brígida-BA was more prevalent (χ2 = 6.416, df = 2 p = 0.040). Inbreeding, as revealed in the evaluated cities, reinforces the hypothesis for developing genetic diseases.

Susceptibility to the novel coronavirus disease (COVID-19) is associated with ABO and Rh blood groups: a case-control study from Afghanistan

Background

There are preliminary studies about the association between COVID-19 and ABO phenotypes and the results are controversial. There are only two studies which investigated the association of Rh blood groups in addition to ABO with COVID-19; however, in the statistical analysis ABO and Rh blood groups have been considered separately. Therefore, the present case-control study was performed to determine the association of COVID-19 with ABO blood groups considering the Rh blood groups simultaneously. The study was conducted in Kunduz COVID-19 treatment specific center, Spin-Zar Hospital (Kunduz Province, North East Afghanistan). A total of 301 confirmed COVID-19 cases and 1039 healthy blood donors as control group were included in the study.

Results

The Rh- phenotype strongly increased the risk of COVID-19 (OR = 2.97, 95% CI 1.86-3.89, P < 0.001). Although blood group A increased the risk of developing COVID-19, the association did not reach statistical significance. In analysis of the combination phenotypes, the A- blood group remarkably increased the risk of COVID-19 (OR = 7.24, 95% CI 3.62-14.4, P < 0.001). Multivariate analysis revealed that the interaction of Rh and ABO is significant (P < 0.013).

Conclusion

These findings indicate that susceptibility to COVID-19 is strongly associated with A- blood group.

The impact of consanguinity on the frequency of inborn errors of metabolism

Inborn errors of metabolism (IEM) are a heterogeneous group of genetic disorders present in all ethnic groups. We investigated the frequency of consanguinity among parents of newborns with IEM diagnosed by neonatal screening. Data were obtained from 15 years of expanded newborn screening for selected IEM with autosomal recessive mode of inheritance, a national screening program of newborns covering the period from 2002 until April 2017. Among the 838,675 newborns from Denmark, the Faroe Islands and Greenland, a total of 196 newborns had an IEM of whom 155 from Denmark were included in this study. These results were crosschecked against medical records. Information on consanguinity was extracted from medical records and telephone contact with the families. Among ethnic Danes, two cases of consanguinity were identified in 93 families (2.15%). Among ethnic minorities there were 20 cases of consanguinity among 33 families (60.6%). Consequently, consanguinity was 28.2 times more frequent among descendants of other geographic place of origin than Denmark. The frequency of consanguinity was conspicuously high among children of Pakistani, Afghan, Turkish and Arab origin (71.4%). The overall frequency of IEM was 25.5 times higher among children of Pakistani, Turkish, Afghan and Arab origin compared to ethnic Danish children (5.35:10,000 v 0.21:10,000). The frequency of IEM was 30-fold and 50-fold higher among Pakistanis (6.5:10,000) and Afghans (10.6:10,000), respectively, compared to ethnic Danish children. The data indicate a strong association between consanguinity and IEM. These figures could be useful to health professionals providing antenatal, pediatric, and clinical genetic services.

An Exploratory Study of Consanguinity and Dental Developmental Anomalies

Background

Consanguinity is known to alter the population structure but the available literature is almost silent on the association of dental conditions with consanguinity.

Aim

The purpose was to assess the various dental developmental anomalies in 6–9 year old children born out of consanguineous and non-consanguineous marriages and its association with their parents.

Design

A cross sectional house–hold survey with a sample size of 2,000 (1,600 non-consanguineous and 400 consanguineous respondents and their parents) using systematic random sampling was planned. Six to nine-year-old children and their parents living in 1,597 households were examined and the information recorded on a pretested self prepared questionnaire. The questionnaire had questions pertaining to personal details, type of consanguineous marriages, history of trauma and examination of dental developmental anomalies.

Results

Multivariate logistic regression showed that non syndromic supernumerary teeth in fathers (p =.009); fusion in mothers (p = 0.002); fusion (p <0.001), nonsyndromic supernumerary teeth (p < 0.001), and microdontia (p = 0.002) in respondents were significantly associated with consanguinity.

Conclusion

A significant association of developmental anomalies in parents with consanguineous marriages and their respondents was observed.

How to cite this article

Khan SY. An Exploratory Study of Consanguinity and Dental Developmental Anomalies. Int J Clin Pediatr Dent, 2018;11(6):513-518

High Y-chromosomal Differentiation Among Ethnic Groups of Dir and Swat Districts, Pakistan

The ethnic groups that inhabit the mountainous Dir and Swat districts of northern Pakistan are marked by high levels of cultural and phenotypic diversity. To obtain knowledge of the extent of genetic diversity in this region, we investigated Y-chromosomal diversity in five population samples representing the three main ethnic groups residing within these districts, including Gujars, Pashtuns and Kohistanis. A total of 27 Y-chromosomal short tandem repeats (Y-STRs) and 331 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) were investigated. In the Y-STRs, we observed very high and significant levels of genetic differentiation in nine of the 10 pairwise between-group comparisons (R_ST 0.179-0.746), and the differences were mirrored in the Y-SNP haplogroup frequency distribution. No genetic differences were found between the two Pashtun subethnic groups Tarklanis and Yusafzais (R_ST = 0.000). Utmankhels, also considered Pashtuns culturally, were not closely related to any of the other population samples (R_ST 0.451-0.746). Thus, our findings provide examples of both associations and dissociations between cultural and genetic legacies. When analyzed within a larger continental-scale context, these five ethnic groups fall mostly outside the previously characterized Y-chromosomal gene pools of the Indo-Pakistani subcontinent. Male founder effects, coupled with culturally and topographically based constraints upon marriage and movement, are likely responsible for the high degree of genetic structure in this region.

CONSANGUINEOUS MARRIAGES AMONG IRANIAN MANDAEANS LIVING IN SOUTH-WEST IRAN

Several studies have indicated that consanguineous marriages (unions between biologically related persons) are associated with increased risk of autosomal recessive diseases and several multifactorial traits. Mandaeans are a closed ethno-religious community living in areas of southern Iraq and Iran (Khuzestan Province). There are currently no data on the prevalence of consanguineous marriages among Mandaeans. The present study was carried out in 2016 to determine the prevalence of consanguinity among Iranian Mandaeans living in Khuzestan Province, south-west Iran. A total of 137 couples (urban areas: 79 couples; rural areas: 58 couples) were included in the study. Information on the consanguineous marriages of the subjects was collected through direct interviews. Marriages were classified by the degree of relationship between couples as double first cousins, first cousins, first cousin once removed, second cousins and unrelated marriages. The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for the population, stratified by rural and urban areas. The overall frequency of consanguinity was found to be 50.7% in urban and 86.2% in rural areas. There was a significant difference between rural and urban areas in types of marriages (χ 2=24.8, df=4, p<0.001) and first cousin marriages (51.8%) were the most common type. The overall α-value was estimated to be 0.0363 for the Iranian Mandaean population.

Evaluation of IL-12RB1, IL-12B, CXCR-3 and IL-17a expression in cases affected by a non-healing form of cutaneous leishmaniasis: an observational study design

INTRODUCTION

Seldom cutaneous leishmaniasis (CL) may present as a lasting and active lesion(s), known as a non-healing form of CL (NHCL). Non-functional type 1 T helper (Th1) cells are assumed the most important factor in the outcome of the disease. The present study aims to assess some molecular defects that potentially contribute to Th1 impairment in NHCL.

METHODS AND ANALYSIS

This prospective observational study will be implemented among five groups. The first and second groups comprise patients afflicted with non-healing and healing forms of CL, respectively. The third group consists of those recovered participants who have scars as a result of CL. Those participants who have never lived or travelled to endemic areas of leishmaniasis will comprise the fourth group. The fifth group comprises participants living in hyperendemic areas for leishmaniasis, although none of them have been afflicted by CL. The aim is to recruit 10 NHCL cases and 30 participants in each of the other groups. A leishmanin skin test (LST) will be performed to assess in vivo immunity against the Leishmania infection. The cytokine profile (interleukin (IL)-12p70, interferon (IFN)-γ, C-X-C motif chemokine ligand (CXCL)-11 and IL-17a) of the isolated peripheral blood mononuclear cells (PBMCs) will be evaluated through ELISA. Real-time PCR will determine the C-X-C motif chemokine receptor (CXCR)-3 and IL-17a gene expression and expression of IL-12Rβ1 will be assessed by flow cytometry. Furthermore, IL-12B and IL-12RB1 mutation analysis will be performed.

DISCUSSION

It is anticipated that the outcome of the current study will identify IL-12B and IL-12RB1 mutations, which lead to persistent lesions of CL. Furthermore, our expected results will reveal an association between NHCL and pro-inflammatory cytokines (IL-12p70, IFN-γ IL-17a and CXCL-11), as well as CXCR-3 expression.

ETHICS AND DISSEMINATION

This study has been approved by a local ethical committee. The final results will be disseminated through peer-reviewed journals and scientific conferences.

CHANGES IN MARRIAGE PATTERNS AMONG THE ARAB COMMUNITY IN ISRAEL OVER A 60-YEAR PERIOD

The aim of this study was to determine the prevalence and trends of various types of consanguineous marriage among the Arab community in Israel over a long time period (1948-2007) by religion and educational level. Data were collected by face-to-face interview of 3173 Arab couples living in Israel in 2007 and 2008. The trend in consanguineous marriages was found to decrease significantly over successive time periods, from 42.5% to 30.9% (p=0.001), and the prevalence of first-cousin and closer marriages decreased, from 23% to 12.7%. Consanguinity was found to be significantly related to religion (p=0.001) and wife's level of education (p=0.028).

Age-standardized Incidence Rates for Leukemia Associated with Consanguineous Marriages in 68 Countries, an Ecological Study

Consanguineous marriage that defines as a union between biologically related persons has a variety of known deleterious correlations with factors that affect public health within human populations. To investigate the association between the mean of inbreeding coefficient (α) and incidence of leukemia, the present ecological study on 68 countries was carried out. Statistical analysis showed that the age-standardized incidence rate of leukemia positively correlated with log₁₀GNI per capita (r=0.699, df=66, P<0.001) and negatively correlated with log_10α (r=−0.609, df=66, P<0.001). Controlling log₁₀GNI per capita, a significant negative correlation between log_10α and the age-standardized incidence rate of leukemia was observed (r=−0.392, df=65, P=0.001). The countries were stratified according to their annual GNI per capita, low and high-income countries with GNI per capita less than and more than 10,000$, respectively. Statistical analysis showed that in high-income countries, after controlling for log₁₀GNI per capita, the correlation between the age-standardized incidence rate of leukemia and log_10α was still significant (r=−0.600, df=36, P<0.001). It should be noted that there was no significant association between the age-standardized mortality rate due to leukemia and log_10α (P>0.05). The present finding indicates that the rate of leukemia, age-standardized for incidence, is lower in countries with a high prevalence of consanguineous marriages.

CONSANGUINITY AND INBREEDING COEFFICIENT IN TRIBAL PASHTUNS INHABITING THE TURBULENT AND WAR-AFFECTED TERRITORY OF BAJAUR AGENCY, NORTH-WEST PAKISTAN

The north-western populations of Pakistan in the Federally Administered Tribal Areas (FATA) adjoining the Pakistan–Afghanistan border are an amalgamation of native and migrated Pashtun tribes. These tribal populations are in transition due to war conditions and geo-political turmoil on both sides of the border since the Soviet invasion in 1979. Bio-demographic and epidemiological data for these tribes are scarce. A prospective cross-sectional sample of 967 males was selected from a representative Pashtun population of Bajaur Agency, and information obtained on bio-demographic variables and marital union types. Analysis of these data revealed that consanguinity was 22.34% and the inbreeding coefficient F was calculated to be 0.0134. The inbreeding coefficient was observed to be higher in subjects who were illiterate, had unskilled jobs and who belonged to younger age categories, extended families and the Tarkalani tribe. Further analyses with respect to temporal variables like subject's age, year of marriage and age at marriage revealed that after a transition in marital union types in the early 80s, there has been a declining trend in the rate of consanguineous unions. Further, consanguineous unions in the parental generation were only 5%, but parental marriage types were predictors of subjects' marital union types. The data further establish that, contrary to a general notion about a high consanguinity rate in Pakistan, consanguineous unions are not common in Bajaur Agency and first cousin marriage is not the preferred type. Furthermore, this research shows that there is a great regional variation in the pattern of consanguinity in Pakistan that needs to be documented in order to draw a more comprehensive picture of the inbreeding coefficient in the country.

Population-genetic influences on genomic estimates of the inbreeding coefficient: a global perspective

BACKGROUND/AIMS

Culturally driven marital practices provide a key instance of an interaction between social and genetic processes in shaping patterns of human genetic variation, producing, for example, increased identity by descent through consanguineous marriage. A commonly used measure to quantify identity by descent in an individual is the inbreeding coefficient, a quantity that reflects not only consanguinity, but also other aspects of kinship in the population to which the individual belongs. Here, in populations worldwide, we examine the relationship between genomic estimates of the inbreeding coefficient and population patterns in genetic variation.

METHODS

Using genotypes at 645 microsatellites, we compare inbreeding coefficients from 5,043 individuals representing 237 populations worldwide to demographic consanguinity frequency estimates available for 26 populations as well as to other quantities that can illuminate population-genetic influences on inbreeding coefficients.

RESULTS

We observe higher inbreeding coefficient estimates in populations and geographic regions with known high levels of consanguinity or genetic isolation and in populations with an increased effect of genetic drift and decreased genetic diversity with increasing distance from Africa. For the small number of populations with specific consanguinity estimates, we find a correlation between inbreeding coefficients and consanguinity frequency (r = 0.349, p = 0.040).

CONCLUSIONS

The results emphasize the importance of both consanguinity and population-genetic factors in influencing variation in inbreeding coefficients, and they provide insight into factors useful for assessing the effect of consanguinity on genomic patterns in different populations.

First survey of the two polymorphisms (Arg194Trp and Arg399Gln) in XRCC1 gene in four Afghanistan populations and comparison with worldwide data

Genetic polymorphisms in gene encoding X-ray repair cross-complementation group 1 (MIM: 194360; XRCC1) have been defined. Previous studies have revealed that there was significant difference between populations for allelic frequency of Arg194Trp (rs. 1799782) and Arg399Gln (rs. 25487) polymorphisms of XRCC1. In order to get more insight into the genetic structure of Afghanistan populations the present study was carried out. Present study was done on 656 (257 Pashtuns, 217 Tajiks, 120 Hazaras, and 62 Uzbeks) unrelated healthy Afghanis refuges living in Fars province (southern Iran). Genotypes for Arg194Trp and Arg399Gln polymorphisms of the XRCC1 were detected by RFLP-PCR method. The prevalence of the 194Trp allele in Pashtuns, Tajiks, Hazaras, and Uzbeks was 0.072, 0.085, 0.108, and 0.145, respectively. The frequency of the 399Gln in Pashtuns, Tajiks, Hazaras, and Uzbeks was 0.362, 0.378, 0.296, and 0.234, respectively. There was significant difference between these ethnic groups for the genotypic distributions of the Arg194Trp (χ(2) = 16.70, df = 6, P = 0.010) and Arg399Gln (χ(2) = 12.67, df = 6, P = 0.049) polymorphisms. Based on the complete dataset, these polymorphisms showed significant linkage disequilibrium. There was significant difference between the ethnic groups for prevalence of the haplotypes (χ(2) = 16.67, df = 6, P = 0.011). Uzbeks showed significant difference with the other ethnic groups (χ(2) = 10.09, df = 2, P = 0.006). The allelic frequencies of 194Trp and 399Gln in Pashtuns and Tajiks seem to be more similar to the Caucasians than the Asian populations. However, Uzbeks seems to be intermediate between Afghanis' Caucasian (Pashtuns and Tajiks) and Asians.