Search Results (154)

Background: The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) was a 3-year, multicenter, randomized controlled trial to test the effects of the MIND diet on cognitive decline in 604 individuals at risk for Alzheimer’s dementia. Here, we describe the genotyping, imputation, and quality control (QC) procedures for the genetic data of trial participants. Methods: DNA was extracted from either whole blood or serum, and genotyping was performed using the Infinium Global Diversity Array. Established sample and SNP QC procedures were applied to the genotyping data, followed by imputation using the 1000 Genomes Phase 3 v5 reference panel. Results: Significant study-site, specimen type, and batch effects were observed. A total of 494 individuals of inferred European ancestry and 58 individuals of inferred African ancestry were included in the final imputed dataset. Evaluation of the imputed APOE genotype against gold-standard sequencing data showed high concordance (98.2%). We replicated several known genetic associations identified from previous genome-wide association studies, including SNPs previously linked to adiponectin (rs16861209, p = 1.5 × 10⁻⁵), alpha-linolenic acid (rs174547, p = 1.3 × 10⁻⁷), and alpha-tocopherol (rs964184, p = 0.003). Conclusions: This dataset represents the first genetic resource derived from a dietary intervention trial focused on cognitive outcomes. It enables investigation of genetic contributions to variability in cognitive response to the MIND diet and supports integrative analyses with other omics data types to elucidate the biological mechanisms underlying cognitive decline. These efforts may ultimately inform precision nutrition strategies to promote cognitive health. Full article

The size of the gluteus medius muscle (GM) in swine significantly impacts both hindlimb conformation and carcass yield, while little is known about the genetic architecture of this trait. This study aims to estimate genetic parameters and identify candidate genes associated with this trait through a genome-wide association study (GWAS). A total of 439 commercial crossbred pigs, possessing both Landrace and Yorkshire ancestry, were genotyped using the Porcine 50K chip. The length and width of the GM were directly measured, and the area was then calculated from these values. The heritabilities were estimated by HIBLUP (V1.5.0) software, and the GWAS was conducted employing the BLINK model implemented in GAPIT3. The heritability estimates for the length, width, and area of the GM were 0.43, 0.40, and 0.46, respectively. The GWAS identified four genome-wide significant SNPs (rs81381267, rs697734475, rs81298447, and rs81458910) associated with the gluteus medius muscle area. The PDE4D gene was identified as a promising candidate gene potentially involved in the regulation of gluteus medius muscle development. Our analysis revealed moderate heritability estimates for gluteus medius muscle size traits. These findings enhance our understanding of the genetic architecture underlying porcine muscle development. Full article

Climate change is jeopardizing global food security, with at least 713 million people facing hunger. To face this challenge, legumes as common beans could offer a nature-based solution, sourcing nutrients and dietary fiber, especially for rural communities in Latin America and Africa. However, since common beans are generally heat and drought susceptible, it is imperative to speed up their molecular introgressive adaptive breeding so that they can be cultivated in regions affected by extreme weather. Therefore, this study aimed to couple an advanced panel of common bean (Phaseolus vulgaris L.) × tolerant Tepary bean (P. acutifolius A. Gray) interspecific lines with Bayesian regression algorithms to forecast adaptation to the humid and dry sub-regions at the Caribbean coast of Colombia, where the common bean typically exhibits maladaptation to extreme heat waves. A total of 87 advanced lines with hybrid ancestries were successfully bred, surpassing the interspecific incompatibilities. This hybrid panel was genotyped by sequencing (GBS), leading to the discovery of 15,645 single-nucleotide polymorphism (SNP) markers. Three yield components (yield per plant, and number of seeds and pods) and two biomass variables (vegetative and seed biomass) were recorded for each genotype and inputted in several Bayesian regression models to identify the top genotypes with the best genetic breeding values across three localities on the Colombian coast. We comparatively analyzed several regression approaches, and the model with the best performance for all traits and localities was BayesC. Also, we compared the utilization of all markers and only those determined as associated by a priori genome-wide association studies (GWAS) models. Better prediction ability with the complete SNP set was indicative of missing heritability as part of GWAS reconstructions. Furthermore, optimal SNP sets per trait and locality were determined as per the top 500 most explicative markers according to their β regression effects. These 500 SNPs, on average, overlapped in 5.24% across localities, which reinforced the locality-dependent nature of polygenic adaptation. Finally, we retrieved the genomic estimated breeding values (GEBVs) and selected the top 10 genotypes for each trait and locality as part of a recommendation scheme targeting narrow adaption in the Caribbean. After validation in field conditions and for screening stability, candidate genotypes and SNPs may be used in further introgressive breeding cycles for adaptation. Full article

Background/Objectives: Cardiovascular diseases are a global health issue with an increasing burden and are exacerbated by hypertension. High blood pressure is partly attributed to genetic variants that are generally not well understood or extensively studied in sub-Saharan African populations. Variants linked to blood pressure have been found through genome-wide association studies (GWASs), which were mostly conducted among European ancestry populations; however, limited research has been undertaken in Africa. The current study evaluated single-nucleotide polymorphisms (SNPs) of PCSK9, ABCA1, LPL, and PON1 in relation to blood pressure measurements of 1839 Ghanaian adults. Methods: Genotypes were extracted from data generated by the H3Africa SNP array. After adjusting for sex, age, smoking, and body mass index (BMI), inferential statistics were used to investigate the relationships between SNPs and blood pressure (BP) indices. Additionally, Bonferroni correction was used to adjust for multiple testing. Results: Diastolic blood pressure (DBP) and the minor allele T of the PCSK9 variant (rs17111557) were positively associated at p = 0.006 after covariate adjustments. Although this novel DBP-associated variant is located in the 3′ untranslated region (3′ UTR) of the PCSK9 gene, in silico functional prediction suggests it is an expression quantitative trait locus (eQTL) that may change the binding site of transcription factors, potentially altering the rate of transcription and impacting DBP in this Ghanaian population. Conclusions: Our findings highlight the role of genetics in hypertension risk and the potential of discovering new therapies targeting isolated diastolic blood pressure in this rural African population. Full article

The most investigated ABCB1 single-nucleotide polymorphisms (SNPs) related to antiseizure medication resistance are rs1045642 (c.3435C>T, p.Ile1145=), rs2032582 (c.2677G>T/A, p.Ala893Ser/Thr), and rs1128503 (c.1236C>T, p.Gly412=). We conducted a literature review to evaluate the genotype frequencies of rs1045642, rs2032582, and rs1128503 SNPs in different ancestries among the drug-resistant and drug-responsive epilepsy groups. Furthermore, we performed effect size and study power analyses and determined the expected sample size to reach a study power of 0.8 for each conducted research. High and very high statistical power for the rs1045642, rs2032582, and rs1128503 polymorphisms was achieved in 58.0, 60.7, and 31.8% of the studies, respectively. The effect sizes (ES) of rs1045642, rs2032582, and rs1128503 ranged from 0.03–1.04, 0.06–0.92, and 0.04–0.64, respectively. The required sample sizes for rs1045642, rs2032582, and rs1128503 ranged from 9–13,000, 12–2600, and 24–5700 participants, respectively. None of the polymorphisms showed a statistically significant association with antiseizure medication resistance in the forest plots. Our analysis provides valuable guidance for future genetic association studies in the field of drug-resistant epilepsy. Full article

A significant proportion of children with Autism spectrum disorder (ASD) experience sleep issues, such as insomnia and other disorders, as assessed by the Sleep Disturbance Scale for Children. Our study investigated the link between six single nucleotide polymorphisms (SNPs) in the melatonin receptor genes MT1 and MT2 and ASD susceptibility, clinical severity and associated sleep problems. A total of 139 ASD children, 82 siblings, and 53 unrelated healthy controls, all of Sardinian ancestry, were studied; among them, 38 children with co-occurring sleep issues were assessed for the outcomes of a rehabilitative program, including behavioral therapy and sleep hygiene. The MT2 rs10830963 G allele is more prevalent in ASD children and their siblings compared to the healthy controls, while rs2119882 (MT1) and rs1562444 (MT2) are associated with DIMS, DA, and SHY. ASD Children carrying the rs2119882 T allele have higher scores for DIMS and DA compared to C allele carriers, and those carrying rs1562444 A allele have higher scores for SHY than G allele carriers. After rehabilitative treatment, homozygous TT carriers of rs2119882 showed less improvement in DIMS symptoms compared to CT and CC carriers. A similar result was observed for AA carriers of SNP rs1562444 about SHY. We may suggest that the MT1 and MT2 variants may serve as useful predictive genetic markers for the severity of sleep disorders in children with ASD, potentially informing the design of more targeted rehabilitative treatments. Full article

In this study, 172 Single-Nucleotide Polymorphisms (SNPs) (94 identity-informative SNPs, 56 ancestry-informative SNPs, and 22 phenotypic-informative SNPs) included in the ForenSeq™ DNA Signature Prep kit/DNA Primer Mix B (Verogen) were used for genotyping DNA samples from a population of twenty-one unrelated subjects, native to Northeast Italy. SNP sequencing was performed with the MiSeq FGx™ Forensic Genomics System (Illumina-Verogen), and data were analyzed using the Universal Analysis Software (UAS) v1.2. Raw data underwent further examination with STRait Razor v3 (SRv3) to compare the target SNPs’ genotype calls made with UAS and to identify the presence of microhaplotypes (MHs) due to SNPs associated with the same target SNP’s amplicon. The allele (haplotype) frequencies, Hardy–Weinberg equilibrium, linkage disequilibrium, number of effective alleles (A_e), and relevant forensic statistic parameters were calculated. Among the 172 SNPs evaluated, 45 unique microhaplotypes were found, comprising a novel sequence variant never previously described. The presence of MHs resulted in an 8.00% rise in the typologies of unique sequences, leading to changes in A_e. Notably, for 12 out of the 94 iiSNPs, the values of A_e exceeded 2.00, which is generally associated with a higher expected heterozygosity and increased power of discrimination. Full article

Rarámuri Criollo (RC) cattle have been raised by the isolated Tarahumara communities of Chihuahua, Mexico, for nearly 500 years, mostly under natural selection and minimal management. RC cattle were introduced to the United States Department of Agriculture-Agricultural Research Service Jornada Experimental Range (RCJER) in 2005 to begin evaluations of beef production performance and their adaptation to the harsh ecological and climatic conditions of the Northern Chihuahuan Desert. While this research unveiled crucial information on their phenotypic plasticity and adaptation, the genetic diversity and structure of the RCJER population remains poorly understood. This study analyzed the genetic diversity, population structure, ancestral composition, and selection signatures of the RCJER herd using a ~64 K SNP array. The RCJER herd exhibits moderate genetic diversity and low population stratification with no evident clustering, suggesting a shared genetic background among different subfamilies. Admixture analysis revealed the RCJER herd represents a distinctive genetic pool within the Criollo cattle breeds, with significant Iberian ancestry. Selection signatures identified candidate genes and quantitative trait loci (QTL) for traits associated with milk composition, growth, meat and carcass, reproduction, metabolic homeostasis, health, and coat color. The RCJER population represents a distinctive genetic resource adapted to harsh environmental conditions while maintaining productive and reproductive attributes. These findings are crucial to ensuring the long-term genetic conservation of the RCJER and their strategic expansion into locally adapted beef production systems in the USA. Full article

Background/Objectives: Type 2 diabetes mellitus (T2DM) and Alzheimer’s disease (AD) are significant global health issues. Epidemiological studies suggest T2DM increases AD risk, though confounding factors and reverse causality complicate this association. This study aims to clarify the causal relationship between T2DM and AD through a systematic review and meta-analysis of Mendelian randomization (MR) studies and a new two-sample MR analysis. Methods: A literature search across major databases was conducted through May 2024 to identify MR studies linking T2DM and AD. Fixed/random-effect models provided pooled odds ratios (ORs) with 95% confidence intervals (CIs), and heterogeneity was assessed with the I² statistic. For our MR analysis, we pooled genetic variants from selected studies and analyzed AD outcomes using IGAP, EADB, and UKB databases. Multiple MR methods, including inverse variance weighted (IVW) and pleiotropy–robust approaches, were applied for validation. Results: Of 271 articles, 8 MR studies were included (sample sizes: 68,905 to 788,989), all from European ancestry. Our meta-analysis found no significant causal link between T2DM and AD (OR = 1.02, 95% CI: 1.00–1.04) with moderate heterogeneity (I² = 31.3%). Similarly, our MR analysis using 512 SNPs as instrumental variables showed no significant associations in IGAP, EADB, or UKB data, which is consistent across sensitivity analyses. Conclusions: This meta-MR and MR analysis revealed no significant causal association between T2DM and AD, indicating that genetic predisposition to T2DM does not appear to causally influence AD risk, though modifiable clinical or environmental aspects of T2DM may still contribute to neurodegenerative processes. Further research should explore other mechanisms linking these conditions. Full article

Microhaplotypes (MHs) are a novel class of genetic markers, exhibiting features that position them as an alternative to STRs and SNPs in addressing challenges commonly encountered in forensic investigations. Additionally, MHs can also offer valuable insights for ancestry inference. However, due to the novelty of MHs, extensive research in different global populations is required before implementation in forensic casework and general research. In this study, individuals from Afghanistan and Somalia were characterized with the Ion AmpliSeq™ MH-74 Plex Research Panel previously developed for forensic genetic purposes. A total of 84 Afghan and 89 Somalian samples were sequenced on the Ion GeneStudio™ S5 System. This led to the identification of 32 and 42 single nucleotide variants in the Afghan and Somalian populations, respectively, that were not included in the former MH definitions. Most of the observed variants were considered to be rare occurrences, being observed one or two times in the dataset. The average values of the effective number of alleles (A_e) were 3.7 for Somalia and 3.6 for Afghanistan—pointing to elevated intrapopulation diversities compared to Europeans. Other parameters (H_o, H_e, PIC, PD, and PE) consistently showed higher average values in the Afghans and Somalis compared to the previously studied populations. PCA and STRUCTURE analyses with 1000 Genomes samples assigned the Somalis to a different cluster than the other sub-Saharan African populations. The analyses also showed higher European and East Asian co-ancestry in the Afghans than in the remaining South Asian populations. The capability of the MH-74 plex to address common kinship problems was evaluated through computational simulations, considering generic thresholds differing by one order of magnitude to assess the FDRs. The median LR > 10¹³ for true siblings when the hypotheses ‘full siblings’ and ‘unrelated individuals’ were compared. As expected, the median LRs were much lower for simulated half-siblings and cousins. This work evaluated the forensic potential of MHs in understudied populations. Overall, the studied panel was versatile and capable of being applied in different forensic applications. Full article

Florida bass (Micropterus salmoides) and largemouth bass (Micropterus nigricans) are iconic sport fish that hybridize readily, influencing fishery management practices. While the Florida bass has been introduced to various U.S. states to create trophy fisheries, its genetic introgression into native populations can lead to ecological and genetic consequences. Recognizing the need to assess Florida bass presence to guide future management directions, diagnostic SNPs were genotyped for 856 putative largemouth bass across 31 sampling locations across the state of West Virginia. Florida bass controls and a reduced representative sample of 226 individuals from 19 sampling locations were sequenced using the genotype-by-sequencing dd-RAD protocol. The results from the two genomic investigations found no Florida bass ancestry in West Virginia populations, suggesting either no introduction or failed reproductive success of Florida bass in the state. Among West Virginia largemouth bass populations, unique genetic ancestries were found predominantly in introduced non-native largemouth bass populations, indicating that the only sub-structuring in the state is a result of stocking non-native ancestries into the state. Genomic diversity was found to be higher in Ohio River pools compared to inland reservoirs, as well as showing higher levels of potential inbreeding. These results underscore the need to preserve the genetic integrity of native Ohio River strain largemouth bass and prevent the introduction of the Florida bass or F₁ hybrids into the Ohio River and other watersheds of West Virginia. Management recommendations include prioritizing the stocking of native strain bass to mitigate inbreeding and avoid introducing Florida bass to conserve genetic diversity. Full article

In the Americas’ leading cocoa-producing countries, more productive clonal cultivars than traditional biclonal hybrids have been created. In Brazil, several disease-resistant and self-compatible clones such as PS 1319, FA 13, and SJ 02 have been selected on producer farms. The CCN 51 clone from Ecuador is also significant in Brazil. This study aimed to analyze these clones concerning their genetic structures using single-nucleotide polymorphisms, productive potential, disease resistance, and the physico-chemical and organoleptic characteristics of the beans. Clone SJ 02 has ancestry from Contamana (40.7%), Iquitos (34.5%), and Amelonado (23.5%). PS 1319 is primarily Amelonado (67.9%), with Criollo (15.7%) and Contamana (15.6%). FA 13 mainly consists of Amelonado (53.5%) and Iquitos (44.1%). Local cultivars of Bahia are mostly Amelonado, with 99.8% in Comum and Parazinho, 97.4% in Maranhão, and 95.5% in Pará. PS 1319, SJ 02, and FA 13 clones were significantly more productive than CCN 51 but did not differ in disease resistance levels. Significant differences were noted among the cultivars in physicochemical traits (fat, caffeine, and theobromine content). Sensorially, SJ 02 outperformed the other cultivars and was comparable to the reference clone BN 34. The findings indicate that Brazil’s elite clones, derived from complex crosses involving Amelonado, Contamana, Iquitos, and Criollo groups, are productive, resistant, and exhibit favorable physico-chemical and organoleptic qualities, making them valuable for future clonal breeding programs. Full article

Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide synthase (NOS) inhibitor associated with vascular disease, which is prevalent in human plasma. Two isoforms of the enzyme dimethylarginine dimethylaminohydrolase (DDAH), DDAH 1 and 2, degrade ADMA. This study investigates the association of DDAH 1 (rs669173, rs7521189) and DDAH 2 gene polymorphisms (rs805305, rs3131383) with the risk of preeclampsia (PE) comorbidity with human immunodeficiency virus (HIV) infection in pregnant women of African ancestry. A total of 405 women were enrolled in this study: 204 were PE, 201 were normotensive pregnant, and 202 were HIV positive. DNA was extracted from whole blood, and SNPs (rs669173, rs7521189, rs805305, and rs3131383) were amplified to detect single-nucleotide polymorphisms (SNPs). After PCR amplification, allelic discrimination was examined. Comparisons were conducted utilizing the Chi-squared test. Our findings indicated that preeclamptic women displayed a greater prevalence of the three variants compared to those with both PE and HIV infection. There is an association between the rs669173 and rs7521189 SNPs of the DDAH 1 gene and rs3131383 of the DDAH 2 gene, which could play a role in reducing the bioavailability of nitric oxide (NO), which affects endothelial function, leading to the development of PE in pregnant women of African ancestry. In contrast, the rs805305 variant of the DDAH 2 gene was not significantly associated with PE development. Interestingly, none of the SNPs investigated correlated with HIV infection or could be attributed to the human allelic variant influence on HIV infection outcome. Full article

Background: Breast cancer (BC), one of the most common cancers, has increased in Mexico during the past decade, along with other chronic and metabolic diseases. Methods: Herein, we analyzed 121 SNPs (85 SNPs related to BC and/or glucose-associated metabolic pathways and 36 SNP classified as ancestry markers) in 92 confirmed BC cases and 126 unaffected BC women from Northeastern Mexico. The relationship of these 121 SNPs with BC, considering BMI, menopause status, and age as cofactors, was explored using a gene–environment (G × E) interaction multi-locus model. Results: Twelve gene variants were significantly associated with BC: three located in exome (rs3856806 PPARG, rs12792229 MMP8, and rs5218 KCNJ11-ABCC8), and nine in non-coding regions, which are involved in accelerated decay of the mRNA transcripts, regulatory regions, and flanking regions (rs3917542 PON1; rs3750804 and rs3750805 TCF7L2; rs1121980 and rs3751812 FTO; rs12946618 RPTOR; rs2833483 SCAF4; rs11652805 AMZ2P1-GNA13; and rs1800955 SCT-DEAF1-DRD4). Conclusions: This study identified an association between BC and menopause, age (above 45), obesity, and overweight status with gene variants implicated in diabetes mellitus, obesity, insulin resistance, inflammation, and remodeling of the extracellular matrix. Full article

In a systematic explorative study of genetic patterns on chromosome 19, we discovered a pattern comprising 23 SNP alleles that is significantly associated with late-onset Alzheimer’s disease (AD). This association was validated using two independent datasets. The pattern includes thimet oligopeptidase (THOP1), which has a long and disputatious relationship with AD. It also spans solute carrier family 39 member 3 (SLC39A3) and small glutamine-rich tetratricopeptide repeat co-chaperone alpha (SGTA) and is upstream from DIRAS family GTPase 1 (DIRAS1). We utilized population data to observe the frequencies of this genetic pattern for 11 different ancestries and noted that it is highly common for Europeans and relatively infrequent for Africans. This research provides a distinct genetic signature for AD risk, as well as insights into the complicated relationship between this disease and THOP1. Full article