Publications by authors named "Samira Asgari"

Infectious disease is the result of interactions between host and pathogen and can depend on genetic variations in both. We conduct a genome-to-genome study of paired human and Mycobacterium tuberculosis genomes from a cohort of 1556 tuberculosis patients in Lima, Peru. We identify an association between a human intronic variant (rs3130660, OR = 10.

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  • Biobank-scale studies often overlook Hispanic/Latino(a) and African American populations, which hinders the understanding of disease-related genetic factors in these groups.
  • The analysis of data from a New York City biobank reveals that phenome-wide admixture mapping (AM) identified 77 significant genetic signals, 48 of which were missed by genome-wide association studies (GWAS), indicating that the two methods complement each other.
  • The study shows that AM can uncover novel genetic associations in underrepresented populations, particularly for variants that traditional GWAS might miss.
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Aims/hypothesis: Type 1 diabetes is associated with excess coronary artery disease (CAD) risk even when known cardiovascular risk factors are accounted for. Genetic perturbation of haematopoiesis that alters leukocyte production is a novel independent modifier of CAD risk. We examined whether there are shared genetic determinants and causal relationships between type 1 diabetes, CAD and leukocyte counts.

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A quarter of humanity is estimated to have been exposed to Mycobacterium tuberculosis (Mtb) with a 5-10% risk of developing tuberculosis (TB) disease. Variability in responses to Mtb infection could be due to host or pathogen heterogeneity. Here, we focused on host genetic variation in a Peruvian population and its associations with gene regulation in monocyte-derived macrophages and dendritic cells (DCs).

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The morphology of cells is dynamic and mediated by genetic and environmental factors. Characterizing how genetic variation impacts cell morphology can provide an important link between disease association and cellular function. Here, we combine genomic sequencing and high-content imaging approaches on iPSCs from 297 unique donors to investigate the relationship between genetic variants and cellular morphology to map what we term cell morphological quantitative trait loci (cmQTLs).

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  • Peripheral artery disease (PAD) affects about 8 million Americans and shows notable racial and ethnic disparities, with higher prevalence in African Americans and varying rates among Hispanic/Latino groups compared to European Americans.
  • In a study of diverse adults in New York City, researchers found PAD rates of 8.5% in African Americans and 9.4% in Hispanic/Latinos, with Puerto Rican and Dominican populations showing even higher rates.
  • Genetic analysis indicated a specific Native American ancestry tract linked to increased PAD risk, although attempts to confirm these findings in other Hispanic groups were not successful.
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A quarter of humanity is estimated to be latently infected with () with a 5-10% risk of developing tuberculosis (TB) disease. Variability in responses to infection could be due to host or pathogen heterogeneity. Here, we focused on host genetic variation in a Peruvian population and its associations with gene regulation in monocyte-derived macrophages and dendritic cells (DCs).

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Article Synopsis
  • - Peripheral artery disease (PAD) affects about 8 million Americans and shows significant racial and ethnic disparities, particularly higher prevalence in African Americans compared to non-Hispanic Europeans.
  • - A study involving diverse participants from the Bio biobank in New York City found PAD prevalence rates of 8.5% in African Americans and 9.4% in Hispanic/Latino individuals, with Puerto Rican and Dominican sub-groups showing even higher rates.
  • - Genetic analysis revealed a specific ancestry tract linked to PAD risk among Dominicans, indicating a potential genetic component that could explain their higher prevalence, especially related to a region on chromosome 2q35 associated with blood vessel health and function.
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The genotyping of millions of human samples has made it possible to evaluate variants across the human genome for their possible association with risks for numerous diseases and other traits by using genome-wide association studies (GWASs). The associations between phenotype and genotype found in GWASs make possible the construction of polygenic scores (PGSs), which aim to predict a trait or disease outcome in an individual on the basis of their genotype (in the disease case, the term polygenic risk score [PRS] is often used). PGSs have shown promise for studying the biology of complex traits and as a tool for evaluating individual disease risks in clinical settings.

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We investigated whether ancestry-specific genetic factors affect tuberculosis (TB) progression risk in a cohort of admixed Peruvians. We genotyped 2,105 patients with TB and 1,320 household contacts (HHCs) who were infected with () but did not develop TB and inferred each individual's proportion of native Peruvian genetic ancestry. Our HHC study design and our data on potential confounders allowed us to demonstrate increased risk independent of socioeconomic factors.

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  • * This study focused on single-cell eQTLs in memory T cells, analyzing over 500,000 cells from 259 individuals and finding that about one-third of eQTLs were linked to complex cell states like cytotoxicity.
  • * The research highlighted that considering continuous cell states offers better insights than traditional categories (e.g., CD4 vs. CD8), emphasizing the importance of cell-state context in understanding autoimmune diseases and eQTL pathogenicity.
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As single-cell datasets grow in sample size, there is a critical need to characterize cell states that vary across samples and associate with sample attributes, such as clinical phenotypes. Current statistical approaches typically map cells to clusters and then assess differences in cluster abundance. Here we present co-varying neighborhood analysis (CNA), an unbiased method to identify associated cell populations with greater flexibility than cluster-based approaches.

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Pharmacogenomic studies have revealed associations between rs1967309 in the adenylyl cyclase type 9 () gene and clinical responses to the cholesteryl ester transfer protein (CETP) modulator dalcetrapib, however, the mechanism behind this interaction is still unknown. Here, we characterized selective signals at the locus associated with the pharmacogenomic response in human populations and we show that rs1967309 region exhibits signatures of positive selection in several human populations. Furthermore, we identified a variant in , rs158477, which is in long-range linkage disequilibrium with rs1967309 in the Peruvian population.

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Despite thousands of reported patients with pandemic-associated pernio, low rates of seroconversion and PCR positivity have defied causative linkage to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pernio in uninfected children is associated with monogenic disorders of excessive IFN-1 immunity, whereas severe COVID-19 pneumonia can result from insufficient IFN-1. Moreover, SARS-CoV-2 spike protein and robust IFN-1 response are seen in the skin of patients with pandemic-associated pernio, suggesting an excessive innate immune skin response to SARS-CoV-2.

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Multimodal T cell profiling can enable more precise characterization of elusive cell states underlying disease. Here, we integrated single-cell RNA and surface protein data from 500,089 memory T cells to define 31 cell states from 259 individuals in a Peruvian tuberculosis (TB) progression cohort. At immune steady state >4 years after infection and disease resolution, we found that, after accounting for significant effects of age, sex, season and genetic ancestry on T cell composition, a polyfunctional type 17 helper T (T17) cell-like effector state was reduced in abundance and function in individuals who previously progressed from Mycobacterium tuberculosis (M.

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On average, Peruvian individuals are among the shortest in the world. Here we show that Native American ancestry is associated with reduced height in an ethnically diverse group of Peruvian individuals, and identify a population-specific, missense variant in the FBN1 gene (E1297G) that is significantly associated with lower height. Each copy of the minor allele (frequency of 4.

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  • The study explores the potential link between primary immunodeficiencies (PID) and susceptibility to sepsis in children, hypothesizing that sepsis may be the first sign of an underlying PID.
  • Researchers conducted whole-exome sequencing (WES) on a national cohort of 176 previously healthy children aged 28 days to under 17 years who were admitted with blood culture-proven sepsis, focusing on rare and predicted pathogenic variants in PID-related genes.
  • They found 41 unique PID variants in 20% of the patients, with some variants previously associated with PID, but no significant correlation was observed between the presence of these variants and clinical characteristics, indicating a need for further research to assess their impact on sepsis
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Of the 1.8 billion people worldwide infected with Mycobacterium tuberculosis, 5-15% will develop active tuberculosis (TB). Approximately half will progress to active TB within the first 18 months after infection, presumably because they fail to mount an effective initial immune response.

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Acute liver failure (ALF) or fulminant hepatitis is a rare, yet severe outcome of infection with hepatitis B virus (HBV) that carries a high mortality rate. The occurrence of a life-threatening condition upon infection with a prevalent virus in individuals without known risk factors is suggestive of pathogen-specific immune dysregulation. In the absence of established differences in HBV virulence, we hypothesized that ALF upon primary infection with HBV could be due to rare deleterious variants in the human genome.

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An inverted (intussuscepted) appendix is a rare finding, often mistaken for a polyp as it presents with vague symptoms. This can result in misdiagnosis and inappropriate management. Diagnosis is usually made through surgery.

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Viral respiratory infections are usually mild and self-limiting; still they exceptionally result in life-threatening infections in previously healthy children. To investigate a potential genetic cause, we recruited 120 previously healthy children requiring support in intensive care because of a severe illness caused by a respiratory virus. Using exome and transcriptome sequencing, we identified and characterized three rare loss-of-function variants in which encodes an RIG-I-like receptor involved in the sensing of viral RNA.

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