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PubMed2025

The role of candidate genetic polymorphisms in covid-19 susceptibility and outcomes.

BACKGROUND: This study aims to investigate the association between candidate host genetic polymorphisms and COVID-19 susceptibility, severity, hospitalization, hypoxia, and their combined effect, measured by the polygenic risk score (PRS). METHODS: Three hundred and seventy-six Lebanese participants, comprising 151 controls and 225 cases, were included. Clinical data were obtained from questionnaires and medical records. DNA isolated from peripheral blood was genotyped for ACE1 rs1799752, ACE2 rs2074192, TMPRSS2 rs75603675 and OAS1 rs107746771 using TaqMan assays, and for TMPRSS2 rs35074065 using Sanger Sequencing. Candidate genetic variants were analyzed in association with COVID-19 susceptibility, severity, hospitalization and hypoxia, using univariate and multivariate models. PRS constructed from the weighted sum of variants was evaluated in association with COVID-19 outcomes. RESULTS: In this study, there were no statistically significant differences in the frequencies of candidate variant alleles between cases, controls and within disease outcomes subgroups, after adjustment for confounders. PRS was not associated with COVID-19 susceptibility and hospitalization, it however significantly predicted COVID-19 severity (P = 0.01). CONCLUSION: This study highlights the importance of genetic testing for key host genes involved in COVID-19 life cycle and eventually measuring the PRS which proves to be an important tool for prognosis assessment in vulnerable individuals, potentially enhancing patient care.

Polymorphism, Genetic↗

PubMed2025

A comprehensive evaluation of candidate genetic polymorphisms in a large histologically characterized MASLD cohort using a novel framework.

BACKGROUND: There is a substantial heritable component to metabolic dysfunction-associated steatotic liver disease (MASLD), and several genetic variants that promote MASLD development or associate with its severity have been reported. These associations vary in terms of their effect size and degree of replication. METHODS: We developed a framework to classify previously identified MASLD genetic polymorphisms into 4 tiers based on effect size and extent of replication in the literature. We tested the association between "tier 1" single-nucleotide polymorphisms (OR ≥1.5, replicated in >2 independent studies) and biopsy measures of MASLD severity in a large, well-characterized histologic cohort of MASLD patients (n=3094). RESULTS: Across 19 "tier 1" variants reflecting 11 genetic loci, only those in the PNPLA3-SAMM50-PARVB locus showed significant associations with biopsy-proven fibrosis severity and NAFLD activity score; the highest risk was for the rs738409 p.I148M variant in PNPLA3. A genetic risk score based on "tier 1" variants, as well as a previously developed genetic risk score based on variants in PNPLA3, TM6SF2, and HSD17B13, were both associated with fibrosis and NAFLD activity score, but these results were driven entirely by PNPLA3 rs738409. CONCLUSIONS: Our study provides a framework to prioritize evaluation of genetic polymorphisms for future replication efforts and demonstrates that in a large case-only cohort, histologic severity of MASLD is only robustly associated with the presence of variation in PNPLA3 among known candidate genes. These findings may have implications for patient risk stratification based on the presence of PNPLA3 rs738409.

Humans↗

PubMed2026

EST-SSR based genetic polymorphism among Lablab (Lablab purpureus L. Sweet) accessions contrasting for drought stress at seedling stage.

Lablab is a multipurpose and the most drought-tolerant (DT) crop compared with its relatives. Despite its potential, Lablab is still an underutilized crop with a lack of improved varieties in many countries. The DT (D349, D147, HA4, D363, D352, D359, D348, D311, D55 and D250) and drought-susceptible (DS) (D271, D66, D106, D6, D26, D255, D28, D186, D95, and D258) accessions were earlier identified according to their morphological and biochemical responses to moisture stress at the seedling stage. These accessions were used to establish genetic polymorphism among the accessions contrasting for drought stress based on the Expressed Sequence Tag-Simple Sequence Repeats (EST-SSR) markers. The CTAB protocol was employed for the genomic DNA extraction. After DNA quality and quantity verification, the PCR was conducted using 16 EST-SSR primer pairs specific to the Lablab. The products were separated through the horizontal polyacrylamide gel electrophoresis (hPAGE). Discriminating ability of the markers and primers' efficiency were evaluated based on various genetic parameters. Principal Coordinate Analysis (PCoA) was performed to estimate the distance matrix among the population and among the accessions. While cluster analysis was processed to trace the genetic relationship among the accessions, dendrogram was constructed to decipher their genetic relationship. Analysis of Molecular Variance (AMOVA) was finally computed to quantify the diversity level and genetic relationship among the population, and among the accessions. A low polymorphism (GD = 0.19) was observed between the DT and DS accessions, likely due to limited discriminatory power of the EST-SSR markers. However, the PCoA, cluster analysis and AMOVA identified DT (D147, HA4, and D349) and DS (D106, D95, and D271) accessions as strongly contrasting populations under drought stress, with D147, HA4, D349, D363, D359, D352, and D348 further recommended as DT accessions. Given the low polymorphism observed, further validation using more informative molecular markers and advanced genomic approaches is recommended to improve the identification of drought-tolerance genes and related QTLs to support Lablab breeding programs.

Expressed Sequence Tags↗

PubMed2026

Analysis of genetic polymorphisms and mRNA expression of DRD3 and HTR2A in bruxism.

BACKGROUND: Bruxism, characterized by the involuntary grinding or clenching of teeth, is influenced by genetic, psychological, and environmental factors. This study aimed to evaluate the role of DRD3 (rs6280) and HTR2A (rs6313) polymorphisms in bruxism and to investigate the expression of these genes to better understand their biological significance. METHODS: This case-control study included 82 bruxism patients and 87 controls. Diagnosis was based on clinical examination and non-instrumental criteria from the 2018 international consensus. Genotyping of HTR2A rs6313 and DRD3 rs6280 was performed using PCR-RFLP, and gene expression in peripheral blood was assessed by qPCR. Statistical analyses included chi-square tests, logistic regression, and mRNA expression analysis using the ΔΔCt method. RESULTS: A significant association was identified between bruxism and the rs6313 polymorphism of the HTR2A gene (p = 0.004; OR = 1.89 [1.23-2.92]), with the C allele associated with increased risk. Moreover, HTR2A mRNA expression was upregulated in individuals with bruxism. While no significant differences were observed in DRD3 rs6280 genotype distribution between cases and controls, the presence of the C allele appeared to increase susceptibility to sleep bruxism. In addition, DRD3 mRNA expression was downregulated in bruxism patients. CONCLUSIONS: These findings highlight a significant association between bruxism and the rs6313 polymorphism of the HTR2A gene. Furthermore, increased HTR2A and decreased DRD3 expression support the involvement of serotonin and dopamine pathways in bruxism etiology, underscoring its multifactorial and complex nature. CLINICAL SIGNIFICANCE: This study elucidates the genetic basis of bruxism, indicating a potential role of serotonin and dopamine signaling in its pathogenesis. Understanding genetic predisposition could aid in early detection, risk assessment, and targeted treatment development. TRIAL REGISTRATION: Clinicaltrials.gov ; trial registration number: NCT06457646 (13/06/2024).

Adult↗

PubMed2024

Genetic polymorphisms affecting telomere length and their association with cardiovascular disease in the Heinz-Nixdorf-Recall study.

Short telomeres are associated with cardiovascular disease (CVD). We aimed to investigate, if genetically determined telomere-length effects CVD-risk in the Heinz-Nixdorf-Recall study (HNRS) population. We selected 14 single-nucleotide polymorphisms (SNPs) associated with telomere-length (p<10-8) from the literature and after exclusion 9 SNPs were included in the analyses. Additionally, a genetic risk score (GRS) using these 9 SNPs was calculated. Incident CVD was defined as fatal and non-fatal myocardial infarction, stroke, and coronary death. We included 3874 HNRS participants with available genetic data and had no known history of CVD at baseline. Cox proportional-hazards regression was used to test the association between the SNPs/GRS and incident CVD-risk adjusting for common CVD risk-factors. The analyses were further stratified by CVD risk-factors. During follow-up (12.1±4.31 years), 466 participants experienced CVD-events. No association between SNPs/GRS and CVD was observed in the adjusted analyses. However, the GRS, rs10936599, rs2487999 and rs8105767 increase the CVD-risk in current smoker. Few SNPs (rs10936599, rs2487999, and rs7675998) showed an increased CVD-risk, whereas rs10936599, rs677228 and rs4387287 a decreased CVD-risk, in further strata. The results of our study suggest different effects of SNPs/GRS on CVD-risk depending on the CVD risk-factor strata, highlighting the importance of stratified analyses in CVD risk-factors.

Humans↗

PubMed2026

Genetic polymorphism in Plasmodium falciparum MSPDBL1 and MSPDBL2 and their impact on B- and T-cell immunodominant epitopes in Brazilian malaria-endemic areas.

Merozoite Surface Protein Duffy Binding-like 1 and 2 (MSPDBL1 and MSPDBL2) are involved in erythrocyte invasion by Plasmodium falciparum. Antibodies targeting PfMSPDBL1 and PfMSPDBL2 show strong opsonizing and growth-inhibitory activities, supporting their potential as asexual blood-stage vaccine candidates. Given that the extensive genetic diversity of P. falciparum contributes to immune evasion, identifying polymorphisms in regions encoding PfMSPDBL1 and PfMSPDBL2 is essential to assess their relevance as vaccine targets. In this study, we investigated polymorphisms in the pfmspdbl1 and pfmspdbl2 genes and their impact on potentially antigenic regions within the Duffy Binding-like (DBL) and Secreted Polymorphic Antigen Associated with Merozoite (SPAM) domains. Blood samples were collected from 47 P falciparum-infected individuals from three malaria-endemic areas of the Brazilian Amazon. Genomic DNA was extracted, PCR-amplified, and sequenced. Intrapopulation genetic diversity and Tajima's D values were estimated using bioinformatics tools. Linear B- and T-cell epitopes were predicted using BCPreds and IEDB (Immune Epitope Database), respectively. Two and thirty-two polymorphisms were identified in pfmspdbl1 within the SPAM and DBL domains, respectively, whereas pfmspdbl2 presented two polymorphisms across both domains and a 12 bp insertion in the SPAM domain. Tajima's D values were positive across domains, except for the DBL domain of pfmspdbl2 in Mâncio Lima. Fifteen B-cell and fifteen T-cell epitopes were predicted, with polymorphisms in three B-cell epitopes affecting Vaxijen scores. Together, these findings reveal contrasting evolutionary patterns between PfMSPDBL1 and PfMSPDBL2, with potential implications for antigenicity, and highlight PfMSPDBL2 as a potential candidate for further evaluation in multicomponent blood-stage malaria vaccine development.

Genetic diversity↗

PubMed2024

Evidence for a relationship between genetic polymorphisms of the L-DOPA transporter LAT2/4F2hc and risk of hypertension in the context of chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) and hypertension are chronic diseases affecting a large portion of the population frequently coexistent and interdependent. The inability to produce/use adequate renal dopamine may contribute to the development of hypertension and renal dysfunction. The heterodimeric amino acid transporter LAT2/4F2hc (SLC7A8/SLC3A2 genes) promotes the uptake of L-DOPA, the natural precursor of dopamine. We examined the plausibility that SLC7A8/SLC3A2 gene polymorphisms may contribute to hypertensive CKD by affecting the L-DOPA uptake. METHODS: 421 subjects (203 men and 218 women, mean age of 78.9 ± 9.6 years) were recruited and divided in four groups according to presence/absence of CKD, defined as reduced estimated glomerular filtration rate (eGFR < 60 ml/min/m2) calculated using the creatinine-based Berlin Initiative Study-1 (BIS1) equation, and to presence/absence of hypertension (systolic blood pressure ≥ 140 and/or diastolic blood pressure ≥ 90 mmHg). Subjects were analysed for selected SNPs spanning the SLC7A8 and SLC3A2 loci by Sequenom MassARRAY iPLEX platform. RESULTS: The most significant SNP at the SLC3A2 (4F2hc) locus was rs2282477-T/C, with carriers of the C-allele having a lower chance to develop hypertension among CKD affected individuals [OR = 0.33 (CI 0.14-0.82); p = 0.016]. A similar association with hypertensive CKD was found for the SLC7A8 (LAT2) rs3783436-T/C, whose C-allele resulted associated with decreased risk of hypertension among subjects affected by CKD [OR = 0.56 (95% CI 0.35-0.90; p = 0.017]. The two variants were predicted to be potentially functional. CONCLUSIONS: The association between SLC3A2 and SLC7A8 variants to hypertension development in patients with renal failure could be linked to changes in L-DOPA uptake and consequently dopamine synthesis. Although the associations do not survive correction for Bonferroni multiple testing, and additional research is needed, our study opens new avenues for future basic and translational research in the field of hypertensive CKD.

Aged↗

PubMed2025

Whole genome sequencing of Yersinia pestis isolates from Central Asian natural plague foci revealed the role of adaptation to different hosts and environmental conditions in shaping specific genotypes.

The genetic diversity and biovar classification of Yersinia isolates from Central Asia were investigated using whole-genome sequencing. In total, 98 isolates from natural plague foci were sequenced using the MiSeq platform. Computational pipelines were developed for accurate assembly of Y. pestis replicons, including small cryptic plasmids, and for identifying genetic polymorphisms. A panel of 99 diagnostic polymorphisms was established, enabling the distinction of dominant Medievalis isolates derived from desert and upland regions. Evidence of convergent evolution was observed in polymorphic allele distributions across genetically distinct Y. pestis biovars, Y. pseudotuberculosis, and other Y. pestis strains, likely driven by adaptation to similar environmental conditions. Genetic polymorphisms in the napA, araC, ssuA, and rhaS genes, along with transposon and CRISPR-Cas insertion patterns, were confirmed as suitable tools for identifying Y. pestis biovars, although their homoplasy suggests limited utility for phylogenetic inference. Notably, a novel cryptic plasmid, pCKF, previously associated with the strain of the population 2.MED0 from the Central-Caucasus high-altitude autonomous plague focus, was detected in a genetically distinct isolate of 2.MED1 population from the Ural-Embi region, indicating potential plasmid transfer across the 2.MED lineage. These findings emphasize the need for ongoing genomic surveillance to monitor the spread of virulence-associated genetic elements and to improve our understanding of Y. pestis evolution and ecology.

Yersinia pestis↗

PubMed2026

Genetic Diversity and Pathogenicity of Thielaviopsis paradoxa Isolates and Implications for Coconut Palm Disease Management.

Thielaviopsis paradoxa is an important soilborne pathogen causing bleeding disease and stem rot of coconut and other palm species, posing a serious threat to coconut production in Hainan Province, China. This study investigated the biological characteristics, pathogenic variability, and genetic diversity of T. paradoxa isolates collected from coconut palms in this region, where population-level data remain limited. Isolates exhibited variability in mycelial growth and sporulation under different temperature, pH, and nutrient conditions, indicating physiological differentiation among strains. Pathogenicity assays across multiple coconut varieties revealed four pathogenicity types, with some isolates consistently showing greater aggressiveness. Genetic analysis based on ISSR markers revealed a high level of genetic diversity (82.96% polymorphism). Genetic clustering showed partial associations with geographic origin, host source, and pathogenicity patterns; however, these relationships are correlative and do not imply causality. Overall, this study provides the first region-specific synthesis of physiological traits, pathogenic variability, and ISSR-based genetic diversity of T. paradoxa in Hainan, contributing baseline information for future population genomic studies and supporting the development of improved disease management strategies for coconut palms.[Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

China↗

PubMed2026

Gene polymorphisms associated with progression of primary open-angle glaucoma: A systematic review.

Glaucoma is the leading global cause of irreversible blindness, with primary open-angle glaucoma (POAG) its most prevalent subtype. While elevated intraocular pressure is a major risk factor, glaucoma progression is multifactorial, influenced by genetic, environmental, vascular and mechanical factors. Genetic polymorphisms have been linked to both POAG susceptibility and progression, yet most studies focus on risk factors for disease onset rather than progression. We provide an overview of the current literature on gene polymorphisms associated with POAG progression. We conducted a systematic search following PRISMA guidelines in MEDLINE, EMBASE, Web of Science, Cochrane Library, Scopus and Public Health Genomics and Precision Health Knowledge Base. Eligible studies investigated associations between genetic variants and structural or functional markers of glaucoma progression in adult-onset POAG patients. Eighteen articles were included. HLA class I haplotypes (A1-B8 and A2-B40) and MYOC.mt1+ carriers showed faster progression of optic nerve head damage. The APOE ε4 allele was linked to faster macular thinning in normal tension glaucoma patients. BDNF rs6265 Val/Val homozygotes exhibited accelerated retinal nerve fiber layer loss, particularly in females. TGFBR3-CDC7 (rs1192415: G) and MYOC.mt1+ carriers experienced accelerated visual field deterioration. Carriers of GAS7 (rs9913911: AA), IL1B (rs1143627: CT and rs16944: CT) and OPTN (rs2234968) had a higher likelihood of requiring surgery. Variants in ABCA1, CDKN2B-AS, eNOS and Piezo1 showed inconclusive results. These findings support a role for genetic polymorphisms in POAG progression and highlight the potential of genetic screening to identify patients at increased risk for rapid disease progression.

Disease progression↗

PubMed2025

Genome-wide association studies in chronic venous disease: A systematic review.

BACKGROUND: Chronic venous disease (CVD) arises from venous hypertension secondary to impaired venous return, causing significant morbidity and diminished quality of life. Genetic factors are likely important in the pathogenesis and susceptibility of a patient to develop CVD. This systematic review summarizes genome-wide association studies (GWASs) that investigate the link between genetic variants and CVD. METHODS: A systematic review was conducted in accordance with the PRISMA guidelines, with the search dates ranging from January 1, 1994, to July 17, 2025. Abstract and full-text screening were completed by two independent reviewers, with any conflicts referred to a third senior reviewer. GWASs in adults investigating links between genetic variants and CVD were included. Exclusion criteria included patients with venous thromboembolism, arterial or diabetic disease, or animal models. RESULTS: Thirteen studies were included after screening 517 studies from a search of PubMed, EMBASE, and Ovid. Database sources included UK Biobank, FinnGen, PopGen, and country- or hospital-specific databases with a majority Caucasian and European patient cohort. A total of 602,760 patients were identified with varicose veins and 3,664,604 control cases that were studied with GWASs and other statistical methods including a two-sample Mendelian randomization approach, functional mapping, and genetic correlations. A variety of statistically significant genetic polymorphisms were identified that can be attributed to the heritability of varicose veins affecting inflammation and immunity (eg, PPP3R1, EBF1, and GATA2), hypertension (eg, CASZ1), and vascular architecture (eg, CASZ1, PIEZO1, and STIM2). Protective variants (eg, GJD3, MMP10, and 4EBP1) were also identified in Finnish populations. However, replication studies showed that these genetic polymorphisms are not generalizable to specific populations. CONCLUSIONS: This systematic review highlights genes contributing to the development of CVD that have been identified in the literature. An improved understanding of genetic contributions to the pathogenesis of CVD may inform future diagnostics, prognostics, and personalized treatment. Further larger scale studies representative of global populations, including meta-analyses of genome-wide association datasets, are required owing to individual GWASs being statistically insufficient to draw generalizable conclusions.

Humans↗

PubMed2026

Pharmacogenomic and drug interactions risk in cardio-oncology: A precision medicine perspective for India.

Cardio-oncology patients may face complex treatment regimens due to the concurrent existence of cancer and cardiovascular disease, leading to a considerable polypharmacy burden. This significantly increases the prospect of drug-drug interactions (DDIs) and gene-drug interactions. The majority of these interactions arise from comparable pharmacokinetic and pharmacological pathways associated with drug transporters and cytochrome P450 enzymes. The significance of pharmacogenomics in tailored treatment strategies are emphasised by the fact that genetic variability enhances individual differences in drug response, safety, and efficacy. This narrative review focus on the effects of key genetic polymorphisms (e.g., DPYD, CYP2C19, and CYP2C9) on the metabolism and efficacy of commonly prescribed anticancer and cardiovascular medications such as fluoropyrimidines, clopidogrel, and warfarin. In addition it explore the role of pharmacogenomic variants on drug-drug interactions within the field of cardio-oncology. The study ultimately emphasizes the necessity of precision medicine in India to address the genetic diversity and underrepresentation in global genomic databases. The absence of pharmacogenomic testing, infrastructural deficiencies, financial constraints, and insufficient clinical integration hinder the widespread use of this technology in India. The Genome India Project and other national initiatives establish the foundation for pharmacogenomic-guided therapy. Utilizing genetic data, together with artificial intelligence-based predictive tools, for clinical decision-making may enhance medication safety and yield optimal outcomes in Indian cardio-oncology patients.

Humans↗

PubMed2026

HLA-DRB1*14 is associated with lower odds of symptomatic SARS-CoV-2 infection in Mexican individuals.

Mexico has been one of the countries most affected by the COVID-19 pandemic. Several factors can influence the susceptibility to SARS-CoV-2 infection, particularly highly polymorphic genes in the HLA system. Therefore, this pilot study analyzed the association between HLA-DRB1 genetic polymorphisms and the susceptibility and/or resistance to symptomatic SARS-CoV-2 infection in a population from the Metropolitan Area of the Valley of Mexico. Individuals with a confirmed SARS-CoV-2 infection were recruited (n = 90), as well as a seronegative control group without reported symptomatic infection (n = 60). The HLA-DRB1 locus was typed using NGS. We found a significant increase in the frequency of the HLA-DRB1*14 allele in the control group (OR = 0.37; 95% CI: 0.18-0.72; p = 0.003; pc = 0.03). These data suggest that HLA-DRB1*14, a prevalent allele in the Mexican population, is associated with a reduced risk of symptomatic SARS-CoV-2 infection in this cohort.

Humans↗

PubMed2026

Multilevel Exploration of Shared Genetic Architecture Between Primary Biliary Cholangitis and Four Autoimmune Diseases.

INTRODUCTION: Primary Biliary Cholangitis (PBC) frequently coexists with various autoimmune diseases, such as Multiple Sclerosis (MS), Psoriasis (PS), Rheumatoid Arthritis (RA), and Sjögren's Syndrome (SS). Understanding the genetic associations between these diseases is crucial for providing deeper insights into their shared pathogenic mechanisms and comorbidity patterns. METHODS: This study utilized genome-wide association study summary data of PBC and four autoimmune diseases (MS, PS, RA, and SS). A multi-stage analytical pipeline was employed to systematically investigate the genetic associations between the diseases. The analytical approach consisted of three stages: first, linkage disequilibrium score regression and high-definition likelihood methods were applied to estimate overall genetic correlations between the diseases; second, local genetic correlation analysis was conducted to pinpoint genetic signals in specific chromosomal regions; third, conditional/conjunctional false discovery rate (cond/conjFDR) algorithms were used to quantitatively assess genetic overlap and identify shared susceptibility loci. RESULTS: Genome-wide analysis revealed significant genetic associations between PBC and the four autoimmune diseases (MS, PS, RA, and SS). Regional analysis showed local genetic correlations across various chromosomal segments. cond/conjFDR analysis confirmed genetic intersections among the diseases and identified several critical genetic polymorphic loci that influence disease susceptibility. DISCUSSION: This study comprehensively delineates the shared genetic architecture underlying PBC and four autoimmune diseases through integrative analyses of multiple genome-wide approaches. The results highlight strong genetic correlations, particularly between PBC and MS, PS, RA, and SS, and identify key shared susceptibility genes, including CLEC16A, CD58, CD86, STAT4, IRF5, TYK2, and TNFAIP3, which collectively mediate immune dysregulation through autophagy, cytokine signaling, and NF-κB pathways. These findings not only extend current understanding of the molecular mechanisms driving autoimmune comorbidity but also provide potential genetic targets for future functional validation and therapeutic exploration. CONCLUSION: This study provides comprehensive genomic evidence for the genetic connections between PBC and the four autoimmune diseases (MS, PS, RA, and SS), offering valuable insights into the shared pathological mechanisms underlying their comorbidities.

Humans↗

PubMed2025

Genetic and epigenetic changes to the glucocorticoid receptor gene (NR3C1) and cognition in major depressive disorder.

INTRODUCTION: Many studies have found that hypothalamic-pituitary-adrenal (HPA) axis abnormalities are related to the pathophysiology of major depressive disorder (MDD) and cognitive functioning. Our aim was to assess the influence of genetic polymorphisms and methylation levels in three different promoter regions throughout the glucocorticoid receptor (GR) gene NR3C1 on cognitive performance in MDD. Plausible interactions with childhood adversity and mediation relationships between genetic and epigenetic variables were explored. MATERIALS AND METHODS: The sample included a total of 64 MDD patients and 82 healthy controls. Child maltreatment and neurocognitive performance were assessed in all participants. HPA negative feedback was analyzed using the dexamethasone suppression test after the administration of 0.25mg of dexamethasone. A total of 23 single-nucleotide polymorphisms were genotyped, and methylation levels at several CpGs in exons 1D, 1F and 1H of the GR gene were measured. RESULTS: Results show that, beyond the influence of other covariables, NR3C1 single-nucleotide polymorphisms and methylation levels predicted performance in executive functioning and working memory tasks. No significant interactions or mediation relationships were detected. CONCLUSIONS: Results suggest that genetic variations and epigenetic regulation of the GR gene are relevant factors influencing cognitive performance in MDD and could emerge as significant biomarkers and therapeutic targets in mood disorders and other stress-related disorders.

Humans↗

PubMed2024

Genotype-phenotype spectrum and correlation of PHARC Syndrome due to pathogenic ABHD12 variants.

BACKGROUND: A comprehensive understanding of the genetic basis of rare diseases and their regulatory mechanisms is essential for human molecular genetics. However, the genetic mutant spectrum of pathogenic genes within the Chinese population remains underrepresented. Here, we reported previously unreported functional ABHD12 variants in two Chinese families and explored the correlation between genetic polymorphisms and phenotypes linked to PHARC syndrome. METHODS: Participants with biallelic pathogenic ABHD12 variants were recruited from the Chinese Deafness Genetics Cohort. These participants underwent whole-genome sequencing. Subsequently, a comprehensive literature review was conducted. RESULTS: Two Han Chinese families were identified, one with a compound heterozygous variant and the other with a novel homozygous variant in ABHD12. Among 65 PHARC patients, including 62 from the literature and 3 from this study, approximately 90% (57 out of 63) exhibited hearing loss, 82% (50 out of 61) had cataracts, 82% (46 out of 56) presented with retinitis pigmentosa, 79% (42 out of 53) experienced polyneuropathy, and 63% (36 out of 57) displayed ataxia. Seventeen different patterns were observed in the five main phenotypes of PHARC syndrome. A total of 33 pathogenic variants were identified in the ABHD12. Compared with other genotypes, individuals with biallelic truncating variants showed a higher incidence of polyneuropathy (p = 0.006), but no statistically significant differences were observed in the incidence of hearing loss, ataxia, retinitis pigmentosa and cataracts. CONCLUSIONS: The diagnosis of PHARC syndrome is challenging because of its genetic heterogeneity. Therefore, exploring novel variants and establishing genotype-phenotype correlations can significantly enhance gene diagnosis and genetic counseling for this complex disease.

Humans↗

PubMed2026

Case Report: Persistent isolated hyperhomocysteinemia in an adolescent with celiac disease and homozygous MTHFR c.665C>T polymorphism: a multifactorial disturbance of one-carbon metabolism.

UNLABELLED: Hyperhomocysteinemia in adolescence typically prompts investigation for classical inborn errors of sulfur amino acid metabolism, including cystathionine β-synthase deficiency and cobalamin-dependent remethylation disorders. However, persistent elevations may also arise from interactions between common genetic polymorphisms and acquired nutritional conditions that alter one-carbon metabolism. CASE PRESENTATION: We report an 18-year-old male with type 1 diabetes mellitus, celiac disease on a strict gluten-free diet, congenital unilateral sensorineural hearing loss, and persistent isolated hyperhomocysteinemia. At age 16, he presented with an acute visual field disturbance and right occipital cortical MRI changes suggestive of ischemia. Plasma homocysteine was persistently between 50 and 65 μmol/L.Extensive metabolic and genetic investigations, including targeted gene panels, whole-exome and research whole-genome sequencing, mitochondrial DNA sequencing, mitochondrial complex activities in fibroblasts, and fibroblast complementation, excluded classical homocystinuria and remethylation defects. Sequential trials of pyridoxine, hydroxocobalamin, and high-dose betaine produced modest or transient improvement. Re-analysis of exome data showed homozygosity for the common MTHFR c.665C>T (p.Ala222Val) variant. Family testing revealed that his father (TT) and mother (CT) had normal homocysteine (10.9 and 10.4 μmol/L), indicating that MTHFR TT alone is insufficient to cause a biochemical phenotype and functions as a susceptibility factor. Combined oral methylfolate (1,000 µg daily) and vitamin B12 (cyanocobalamin 1,000 µg daily) reduced homocysteine from 66 to 24.6 μmol/L in 8 weeks. CONCLUSION: This case illustrates multifactorial hyperhomocysteinemia arising from interactions between celiac disease-related micronutrient vulnerability and reduced MTHFR activity. Recognition of gene-nutrient interactions is important when classical metabolic disorders are excluded and may guide targeted therapy.

MTHFR polymorphism↗

PubMed2015

Variation in Drosophila melanogaster central metabolic genes appears driven by natural selection both within and between populations.

In this report, we examine the hypothesis that the drivers of latitudinal selection observed in the eastern US Drosophila melanogaster populations are reiterated within seasons in a temperate orchard population in Pennsylvania, USA. Specifically, we ask whether alleles that are apparently favoured in northern populations are also favoured early in the spring, and decrease in frequency from the spring to autumn with the population expansion. We use SNP data collected for 46 metabolic genes and 128 SNPs representing the central metabolic pathway and examine for the aggregate SNP allele frequencies whether the association of allele change with latitude and that with increasing days of spring-autumn season are reversed. Testing by random permutation, we observe a highly significant negative correlation between these associations that is consistent with this expectation. This correlation is stronger when we confine our analysis to only those alleles that show significant latitudinal changes. This pattern is not caused by association with chromosomal inversions. When data are resampled using SNPs for amino acid change the relationship is not significant but is supported when SNPs associated with cis-expression are only considered. Our results suggest that climate factors driving latitudinal molecular variation in a metabolic pathway are related to those operating on a seasonal level within populations.

Adaptation, Physiological↗