abstract: Migraine is a primary headache disorder with neurovascular involvement. Migraine with aura is a subtype that accounts for approximately 15%–40% of all migraine cases. Several studies have shown that the global prevalence of migraine varies depending on the population studied. The population of Buenos Aires Province has an admixed genetic background. Several genetic association studies on migraine have been reported; however, most of them were conducted in cohorts of European ancestry, introducing a bias that overlooks global population diversity. DNA was extracted from 310 individuals (153 cases and 157 controls). Genotypes were determined using allele-specific polymerase chain reaction and polymerase chain reaction–restriction fragment length polymorphism techniques for the following polymorphisms: rs2075968 ( PRDM16 ), rs12134493 ( TSPAN2 ), rs10166942 ( TRPM8 ), rs10456100 ( KCNK5 ), rs4910165 ( IRAG1 ), rs11031122 ( MPPED2 ), rs11172113 ( LRP1 ), and rs6081613 ( SLC24A3 ). A case-control analysis was conducted using logistic regression models. All markers were in Hardy-Weinberg equilibrium in the case group. In the control group, however, rs4910165 ( IRAG1 ) deviated from equilibrium and was therefore excluded from the association analysis ( p = .0032). Although codominant and dominant models including all markers simultaneously did not yield significant results, in a single-marker analysis, a trend was suggested for the AA genotype of rs2075968 ( PRDM16 ) under a codominant model ( p = .027, OR = 0.42, 95% CI = 0.20–0.91). These exploratory findings suggest a potential protective role of the AA genotype of rs2075968 ( PRDM16 ) in migraine with aura in the Buenos Aires Province population. Further studies involving additional PRDM16 variants and larger sample sizes are needed to confirm and expand upon these results.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most prevalent enzyme deficiency of human erythrocytes, affecting more than 500 million people globally. G6PD deficiency is the most com- mon hemolytic X-linked genetic disease, which shows a higher prevalence rate in the malaria-endemic population. This review essay aims to examine the overall frequency of G6PD deficiency in the Indian population using systemic review, with a special emphasis on the differential prevalence rate across populations. PubMed, Google Scholar, and ScienceDirect databases were searched to examine the scientific studies focusing on the prevalence of G6PD deficiency among Indian populations. A total of 32 studies were selected after following several inclusion-exclusion criteria, which comprised a total of 115,300 participants. It is observed that the G6PD deficiency is higher among males than females, which is expected as this enzymopathy is caused by inherited mutations of the X-linked gene G6PD. Moreover, the disorder is considerably greater among populations that prefer consanguineal and endogamous marriages, such as Parsi, Muslim, and tribal populations, as compared with nontribal and caste populations. Hence, culturally based marriage practices may help to explain differences in the frequency of this hemolytic genetic disorder among Indian populations.
ABSTRACT: Sickle cell anemia occurs in individuals who are homozygous for the sickle hemoglobin (HbS) allele. The haplotypes of the HbS alleles can be traditionally ascertained through the analysis of five to eight informative restriction fragment length polymorphisms within the HBB gene cluster, defining the five major HbS haplotypes, commonly referred to as Bantu or Central African Republic (CAR), Benin (BEN), Cameroon (CAM), Senegal (SEN), and Arab-Indian. In a recent study, it was suggested that four single nucleotide polymorphisms (SNPs)—rs3834466, rs28440105, rs10128556, and rs968857—are sufficient to characterize most of the HbS haplotypes. In the present study, we investigated the HbS haplotypes in a population sample from São Tomé e Príncipe (Central Africa) by analyzing this set of four SNPs. Additionally, we included the HBG2 rs7482144 (−158C>T) SNP, which is commonly used in the classical HbS haplotype classification, to compare the HbS haplotypes derived from the two different plex systems. Blood samples of 50 heterozygous (HbAS), nine homozygous (HbSS), and three normal HbAA individuals were engaged in this study. Genotyping was performed by the polymerase chain reaction–restriction fragment length polymorphism method. Haplotypes were derived using the Arlequin software. In the 4-plex system, seven different haplotypes were inferred among the 68 HbS chromosomes, corresponding to CAR, 36.8%; BEN, 25.0%; CAM, 13.2%; SEN, 11.8%; and three different sets of unknown HbS haplotypes, 11.4%. The further inclusion of rs7482144 (XmnI) led to the inference of a total of eight distinct HbS haplotypes as follows: CAR, 36.8%; BEN, 25.0%; CAM, 13.2%; SEN, 8.8%; and four different clusters of unknown HbS haplotypes, 16.2%. Using only the nine homozygous HbSS individuals, the same five different haplotypes were identified for both systems, with all common haplotypes occurring at equal frequencies: CAR, 27.8%; BEN, 38.9%; CAM, 16.7%; and SEN, 11.1%. One atypical haplotype was identified at a frequency of 5.6%. Our findings suggest that the 4-plex system may not be entirely accurate in identifying the SEN haplotype when considering heterozygous individuals for the HbS allele in the study population. Additionally, the haplotype background of HbS observed in the S. Tomean population provided further insights compared with previous reports.
abstract: Genetic and archaeological studies indicate that the American continent has undergone multiple waves of human migration, shaping a complex population genetic structure comprising three major ethnic groups—Native American, European, and African—unevenly distributed across the continent. In this study, we examined MAPT (17q21.31) haplotype and subhaplotype frequencies by analyzing two single nucleotide polymorphism markers (rs10514879 and rs199451) in three South American groups from distinct countries: Waorani (Ecuadorian Amazon), Jujuy (northwestern Argentina), and Afro-Colombian (northwestern Colombia). To broaden the scope, we also genotyped four short tandem repeats within the 17q21.31 chromosomal region and compiled H2 haplotype and subhaplotype frequency data for 97 worldwide populations (Africa: 26; Asia: 37; Europe: 19; America: 15). We used the publicly available genome-wide databases 1000G and ALFRED. Genetic heterogeneity among population clusters, classified by geographic region, was examined by hierarchical analysis of molecular variance. Likewise, we explored genetic affinities between the Waorani, Afro-Colombian, and Jujuy samples and worldwide collections using factorial correspondence analysis. The H1 haplotype predominated in all study populations. Notably, H2 varied among them: In Afro-Colombians, H2 was found at a frequency of 0.058, with equal representation of subhaplotypes H2’ and H2D. Among Native American groups (Waorani and Jujuy), the H2 haplotype was virtually absent, with only H2D detected in Jujuy at a very low frequency (0.007). Analysis of a set of short tandem repeats from the MAPT region identified distinct genetic features in Native American groups, characterized by markedly low heterozygosity. Waorani and Karitiana exhibited strikingly low genetic diversity, reflecting a significant degree of population isolation and, consequently, a potentially strong impact of genetic drift. In summary, our analyses demonstrate the utility of MAPT haplotypes in detecting the effects of population isolation, genetic drift, and admixture on the gene pool of the South American samples examined. MAPT haplotypes may serve as reliable lineage markers, given their ability to differentiate ethnic groups and trace ancestral chromosomes. They have proved to be an informative and cost-effective tool for exploring ancestry, geographic origins, and demographic history in anthropological studies.
