Genome-wide association analyses reveal susceptibility variants linked to Parkinson's disease in the South African population using inferred global and local ancestry.

Genome-wide association studies (GWAS) have been successful in identifying over 100 loci associated with Parkinson's disease (PD) susceptibility. However, the majority of these studies have focused on European cohorts with few including diverse ancestries. Using genotyped and imputed data from 691 South African PD cases and 826 controls, we conducted a conventional GWAS, two local ancestry GWAS (LA-GWAS) approaches (one using local ancestry as a covariate and the other separating the dosage per ancestry), and an association analysis to identify regions of homozygosity associated with PD status.

Confirmation of HLA-II associations with TB susceptibility in admixed African samples.

Previously, the International Tuberculosis Host Genetics Consortium (ITHGC) demonstrated the power of large-scale GWAS analysis across diverse ancestries in identifying tuberculosis (TB) susceptibility loci (Schurz et al., 2024). Despite identifying a significant genetic correlate in the human leukocyte antigen (HLA)-II region, this association did not replicate in the African ancestry-specific analysis, due to small sample size and the inclusion of admixed samples.

Uncharted territory: the role of mitochondrial DNA variation in macrophage-mediated host susceptibility to tuberculosis.

Mitochondria form an integral, yet frequently underappreciated, part of the immune response to Mycobacterium tuberculosis (M.tb), particularly within macrophages. Despite growing recognition for their role in infection and immunity, studies investigating how mitochondrial DNA (mtDNA) variation influences host susceptibility to tuberculosis (TB) are limited.

Assessment of physician preparedness for implementation of pathology-supported genetic testing: solution-driven post-COVID-19 survey.

Introduction: Rapid advances in personalized medicine and direct-to-consumer genomic applications could increase the risk that physicians will apply genomic results inappropriately. To address a persistent lack of understanding of genomics, we implemented a pathology-supported genetic testing (PSGT) approach, guided by insights from a clinician needs assessment conducted in 2010.

Methods: Findings from the previous clinician survey were used to develop a new patient screening tool that integrates non-communicable disease (NCD) and post-COVID-19 care pathways.

Methodologies underpinning polygenic risk scores estimation: a comprehensive overview.

Polygenic risk scores (PRS) have emerged as a promising tool for predicting disease risk and treatment outcomes using genomic data. Thousands of genome-wide association studies (GWAS), primarily involving populations of European ancestry, have supported the development of PRS models. However, these models have not been adequately evaluated in non-European populations, raising concerns about their clinical validity and predictive power across diverse groups.

Data Harmonization Guidelines to Combine Multi-platform Genomic Data from Admixed Populations and Boost Power in Genome-Wide Association Studies.

Data harmonization involves combining data from multiple independent sources and processing the data to produce one uniform dataset. Merging separate genotypes or whole-genome sequencing datasets has been proposed as a strategy to increase the statistical power of association tests by increasing the effective sample size. However, data harmonization is not a widely adopted strategy due to the difficulties with merging data (including confounding produced by batch effects and population stratification).

Safety and efficacy of inhaled IBIO123 for mild-to-moderate COVID-19: a randomised, double-blind, dose-ascending, placebo-controlled, phase 1/2 trial.

Background: COVID-19 severity is associated with its respiratory manifestations. Neutralising antibodies against SARS-CoV-2 administered systemically have shown clinical efficacy. However, immediate and direct delivery of neutralising antibodies via inhalation might provide additional respiratory clinical benefits.

GWAS in the southern African context.

Researchers would generally adjust for the possible confounding effect of population structure by considering global ancestry proportions or top principle components. Alternatively, researchers would conduct admixture mapping to increase the power to detect variants with an ancestry effect. This is sufficient in simple admixture scenarios, however, populations from southern Africa can be complex multi-way admixed populations.

Local Ancestry Adjusted Allelic Association Analysis Robustly Captures Tuberculosis Susceptibility Loci.

Pulmonary tuberculosis (TB), caused by , is a complex disease. The risk of developing active TB is in part determined by host genetic factors. Most genetic studies investigating TB susceptibility fail to replicate association signals particularly across diverse populations.

Prospective avenues for human population genomics and disease mapping in southern Africa.

Population substructure within human populations is globally evident and a well-known confounding factor in many genetic studies. In contrast, admixture mapping exploits population stratification to detect genotype-phenotype correlations in admixed populations. Southern Africa has untapped potential for disease mapping of ancestry-specific disease risk alleles due to the distinct genetic diversity in its populations compared to other populations worldwide.