CONSANGUINEOUS MARRIAGES IN AFGHANISTAN

Exploring the diversity of CFTR gene mutations in cystic fibrosis individuals of South Asia

OBJECTIVE

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. This study aimed to identify the spectrum of CFTR variants reported in individuals with CF from South Asia (ISA).

DATA SOURCES AND STUDY SELECTION

We conducted a PubMed search for CFTR variants reported in ISA. Full text of original articles and case reports was read to compile data on reported variants. To gather additional data, we independently cross-referenced each variant with the CFTR Mutation Database and ClinVar.

RESULTS

Our investigation identified a total of 92 CFTR variants reported across 30 articles. The most frequently tested, and reported variant was ΔF508 with a global frequency of 69.74%. Notably, we found 14 pathogenic CFTR mutations shared among ISA, originating from more than one South Asian country: ΔF508, 1525-1 G > A, G542X, S549N, R117H, S549R, R709X, V456A, Y569D, L1077P, 1161delC, 1898 + 1 G > T, G551D, and 2184insA.

CONCLUSION

In summary, the higher prevalence of consanguinity and the limited availability of CF diagnostic resources in South Asia considerably contribute to the prevalence of genetic disorders like CF. The spectrum of CFTR mutations exhibits noticeable variations within South Asian and other populations. The inclusion of current study-enlisted CFTR gene variants is highly recommended for CF disease genetic testing in South Asia which may aid in achieving a precise diagnosis, enhancing disease management, and discovering drugs for currently untreatable genetic variants. It is also imperative to conduct a comprehensive study in this region, especially in previously unexplored countries such as Nepal, Bhutan, Maldives, and Bangladesh.

Consanguineous marriage and associated diseases among their children and grandchildren in India: evidence from large-scale data

Worldwide, more than 130 million infants are born each year and a considerable number of 13.5 million of these children have inbred parents. The present study aimed to investigate the association between parents' consanguinity and chronic illness among their children and grandchildren in India. The nationally representative data, Longitudinal Aging Study in India, 2017-2018, Wave 1 was used for the present study. Bivariate analysis, a probit model, and propensity score estimation were employed to conduct the study. The study observed the highest prevalence of consanguinity marriage in the state of Andhra Pradesh (28%) and the lowest in Kerala (5%) among the south Indian States. People who lived in rural areas, belonged to the richer wealth quintile and Hindu religion were the significant predictors of consanguinity marriage in India. For individuals who were in consanguineous marriages, there was 0.85%, 0.84%, 1.57% 0.43%, 0.34%, and 0.14% chances of their children and grandchildren developing psychotic disorders, heart disease, hypertension stroke, cancer, and diabetes, respectively. Moreover, around 4.55% of the individuals have a history of birth defects or congenital disorders. To address the risk of complicated illnesses due to the consanguinity of marriage, medical, genetic, and social counselling services are required.

Diagnosis and clinical relevance of co-inheritance of haemoglobin D-Punjab/β+-thalassemia traits in an immigrant Afghan family

We report on a Pashtun family affected by haemoglobin D-Punjab/β+-thalassemia to increase the awareness of the increasing prevalence of haemoglobinopathies among primary care physicians. We highlight the diagnostic approach of these conditions and the benefits of genetic counselling.

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.

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.

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.

Association between inbreeding coefficient and susceptibility to HIV-1 infection, a case-control study

INTRODUCTION

Consanguinity has been associated with adverse health outcomes. The objective of the present study was to assess the association between parental consanguinity and risk of infection with human immunodeficiency virus type-1 (HIV-1).

METHODS

Data were collected from 333 HIV-1 infected individuals referred to a local health center in Shiraz (southern Iran). A total of 999 healthy individuals frequency matched with the cases according to their sex and age were also studied, as a control group.

RESULTS

Prevalence of parental consanguineous marriage was 23.7% and 32.8% among patients and controls, respectively (Chi(2)=9.880, df=1, p=0.007). The mean inbreeding coefficient was 0.0110 and 0.0156 among patients and controls, respectively. The risk of infection with HIV-1 decreased as a function of inbreeding coefficient (Chi(2)=7.531, p=0.006).

CONCLUSION

The present finding indicates a negative association between the susceptibility of HIV-1 infection and the inbreeding coefficient.

CIVIL UNREST AND THE CURRENT PROFILE OF CONSANGUINEOUS MARRIAGE IN KHYBER PAKHTUNKHWA PROVINCE, PAKISTAN

Information on the current prevalence and types of consanguineous marriages in Malakand District, Khyber Pakhtunkhwa Province (KPK), Pakistan, was collected from 1192 rural couples. Some 66.4% of marriages were between couples related as second cousins or closer (F≥0.0156), equivalent to a mean coefficient of inbreeding (α) of 0.0338. The data suggest that the prevalence of consanguineous unions in Malakand has been increasing during the last decade, in response to the high levels of violence across KPK.

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.

PREVALENCE OF CONSANGUINEOUS MARRIAGES AMONG SHI'A POPULATIONS OF LEBANON

In genetics, a consanguineous marriage means union between couples who are related as second cousins or closer. The present cross-sectional study was carried out in order to illustrate the prevalence and types of consanguineous marriages in the Shi'a population living in widespread territories in Lebanon including the Bekaa Valley, the south of Lebanon and the southern suburb of Beirut. Data on types of marriages were collected using a simple questionnaire. The total number of couples in the study was 1203. Consanguineous marriage was classified by the degree of relationship between couples. The overall frequency of consanguinity was found to be 28.4%, with first cousin marriages (21.3%) being the most common type followed by first cousins once removed (5.5%), then double first cousins (0.8%). The frequencies of second cousin and beyond second cousin marriages were the same at 0.4% of all the marriages. The mean inbreeding coefficient (α) was estimated at about 0.0161 for the population. There were no significant differences between the three studied territories for frequencies of different types of marriages (p>0.1), nor were there significant differences between the rural and urban areas (p>0.1).

Prevalence of consanguineous marriages in west and south of Afghanistan

The prevalence of consanguinity in eight provinces of Afghanistan has recently been reported by Saify & Saadat (2012). The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages among other populations of Afghanistan. Data on types of marriages were collected using a simple questionnaire. The total number of couples in this study was 5200 from the following provinces: Farah, Ghazni, Herat, Hilmand, Kabul, Kandahar, Logar, Parwan and Wardak. Consanguineous marriages were classified by the degree of relationship between couples: double first cousins, first cousins, first cousins once removed, second cousins and beyond second cousins. The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for each population. The α in the country was 0.0226, ranging from 0.0203 in Farah province to 0.0246 in Herat province. There were significant differences between provinces for frequencies of different types of marriages (p<0.001). First cousin marriages (21.7%) were the most common type of consanguineous marriages, followed by second cousins (16.0%), first cousins once removed (14.0%), beyond second cousins (6.9%) and double first cousins (1.6%). There was significant difference between ethnic groups for the types of marriages (p<0.001). Tajiks (Soni) and Sadats showed the lowest (α=0.0215) and highest (α=0.0242) levels of consanguinity among ethnic groups in Afghanistan, respectively. The present study shows that the Afghani populations, the same as other Islamic populations, have high levels of consanguinity.

Genetic polymorphisms of glutathione S-transferase T1 (GSTT1) and M1 (GSTM1) in selected populations of Afghanistan

Genetic polymorphisms in genes encoding glutathione S-transferase T1 (GSTT1, a member of class theta) and M1 (GSTM1, a member of class mu) have been defined. Previous studies have revealed that there was significant difference between populations for allelic frequency of several members of GSTs. In order to find the prevalence of null genotypes of GSTM1 and GSTT1 in Afghanis populations the present study was carried out. The total study subjects consisted of 656 unrelated healthy Afghanis refugees living in Fars province (southern Iran). From these 257, 217, 120, and 62 individuals were Pashtuns, Tajiks, Hazaras, and Uzbeks, respectively. Genetic polymorphisms for GSTT1 and GSTM1 were detected by multiplex PCR. The prevalence of null genotype of GSTM1 in Pashtuns, Tajiks, Hazaras, and Uzbeks was 42.4, 48.4, 52.5, and 40.3 %, respectively. There was no significant difference between these populations for the genotypic distribution of the GSTM1 polymorphism (χ(2) = 4.67, df = 3, P = 0.197). The frequency of GSTT1 null genotype in Pashtuns, Tajiks, Hazaras, and Uzbeks was 7.4, 25.3, 25.0, and 29.0 %, respectively. The observed difference between populations for prevalence of GSTT1 null genotype was statistically significant (χ(2) = 35.54, df = 3, P < 0.001). In comparison with European and Asian populations, Afghanistan populations like Iranian populations showed intermediate frequency for GSTT1 and GSTM1 null genotypes.