Association between telomere length and Plasmodium falciparum malaria endemicity in sub-Saharan Africans.

Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n = 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon. We observe significant variation in LTL among populations, finding that the San hunter-gatherers from Botswana have the longest leukocyte telomeres and that the Fulani pastoralists from Cameroon have the shortest telomeres. Genetic factors explain ∼50% of LTL variation among individuals. Moreover, we observe a significant negative association between Plasmodium falciparum malaria endemicity and LTL while adjusting for age, sex, and genetics. Within Africa, adults from populations indigenous to areas with high malaria exposure have shorter LTL than those in populations indigenous to areas with low malaria exposure. Finally, we explore to what degree the genetic architecture underlying LTL in Africa covaries with malaria exposure.

Prediction of post-hepatectomy liver failure by preoperative gadoxetate disodium-enhanced magnetic resonance imaging.

BACKGROUND: Approximately 15% of patients experience post-hepatectomy liver failure after major hepatectomy. Poor hepatocyte uptake of gadoxetate disodium, a magnetic resonance imaging contrast agent, may be a predictor of post-hepatectomy liver failure. METHODS: A retrospective cohort study of patients undergoing major hepatectomy (≥3 segments) with a preoperative gadoxetate disodium-enhanced magnetic resonance imaging was conducted. The liver signal intensity (standardized to the spleen) and the functional liver remnant was calculated to determine if this can predict post-hepatectomy liver failure after major hepatectomy. RESULTS: In 134 patients, low signal intensity of the remnant liver standardized by signal intensity of the spleen in post-contrast images was associated with post-hepatectomy liver failure in multiple logistic regression analysis (Odds Ratio 0.112; 95% CI 0.023-0.551). In a subgroup of 33 patients with lower quartile of functional liver remnant, area under the curve analysis demonstrated a diagnostic accuracy of functional liver remnant to predict post-hepatectomy liver failure of 0.857 with a cut-off value for functional liver remnant of 1.4985 with 80.0% sensitivity and 89.3% specificity. CONCLUSION: Functional liver remnant determined by gadoxetate disodium-enhanced magnetic resonance imaging is a predictor of post-hepatectomy liver failure which may help identify patients for resection, reducing morbidity and mortality.

Integrative functional genomic analyses identify genetic variants influencing skin pigmentation in Africans.

Skin color is highly variable in Africans, yet little is known about the underlying molecular mechanism. Here we applied massively parallel reporter assays to screen 1,157 candidate variants influencing skin pigmentation in Africans and identified 165 single-nucleotide polymorphisms showing differential regulatory activities between alleles. We combine Hi-C, genome editing and melanin assays to identify regulatory elements for MFSD12, HMG20B, OCA2, MITF, LEF1, TRPS1, BLOC1S6 and CYB561A3 that impact melanin levels in vitro and modulate human skin color. We found that independent mutations in an OCA2 enhancer contribute to the evolution of human skin color diversity and detect signals of local adaptation at enhancers of MITF, LEF1 and TRPS1, which may contribute to the light skin color of Khoesan-speaking populations from Southern Africa. Additionally, we identified CYB561A3 as a novel pigmentation regulator that impacts genes involved in oxidative phosphorylation and melanogenesis. These results provide insights into the mechanisms underlying human skin color diversity and adaptive evolution.

Comparison of epidural infusion versus intrathecal morphine block as part of enhanced recovery after open pancreatoduodenectomy.

BACKGROUND AND OBJECTIVES: The accepted approach to pain management following open pancreatoduodenectomy (PD) remains controversial, with the most recent enhanced recovery after surgery (ERAS) protocols recommending epidural anesthesia (EA). Few studies have investigated intrathecal (IT) morphine, combined with transversus abdominis plane (TAP) blocks. We aim to compare the different approaches to pain management for open PD. METHODS: Patients who underwent open PD at our institution from 2020 to 2022 were included in the study. Patient characteristics, pain management, and postoperative outcomes between EA, IT morphine with TAP blocks, and TAP blocks only were compared using univariate analysis. RESULTS: Fifty patients were included in the study (58% male, median age 66 years [interquartile range, IQR: 58-73]). Most patients received IT morphine (N = 24, 48%) or EA (N = 18, 36%). The TAP block-only group required higher doses of postoperative narcotics while hospitalized (p = 0.004) and at discharge (p = 0.017). The IT morphine patients had a shorter median time to Foley removal (p = 0.007). Postoperative pain scores, non-opioid administration, postoperative bolus requirements, postoperative outcomes, and length of stay were similar between pain modalities. CONCLUSIONS: IT morphine and EA showed comparable efficacy with superior results compared to TAP blocks alone. Integration of IT morphine into PD ERAS protocols should be considered.

The blobulator: a webtool for identification and visual exploration of hydrophobic modularity in protein sequences.

Motivation: Clusters of hydrophobic residues are known to promote structured protein stability and drive protein aggregation. Recent work has shown that identifying contiguous hydrophobic residue clusters (termed "blobs") has proven useful in both intrinsically disordered protein (IDP) simulation and human genome studies. However, a graphical interface was unavailable. Results: Here, we present the blobulator: an interactive and intuitive web interface to detect intrinsic modularity in any protein sequence based on hydrophobicity. We demonstrate three use cases of the blobulator and show how identifying blobs with biologically relevant parameters provides useful information about a globular protein, two orthologous membrane proteins, and an IDP. Other potential applications are discussed, including: predicting protein segments with critical roles in tertiary interactions, providing a definition of local order and disorder with clear edges, and aiding in predicting protein features from sequence. Availability: The blobulator GUI can be found at www.blobulator.branniganlab.org, and the source code with pip installable command line tool can be found on GitHub at www.GitHub.com/BranniganLab/blobulator.

Disparities in Surgical Treatment of Resectable Pancreatic Adenocarcinoma at Minority Serving Hospitals.

INTRODUCTION: Minority serving hospitals (MSH) are those serving a disproportionally high number of minority patients. Previous research has demonstrated that treatment at MSH is associated with worse outcomes. We hypothesize that patients treated at MSH are less likely to undergo surgical resection of pancreatic adenocarcinoma compared to patients treated at non-MSH. METHODS: Patients with resectable pancreatic cancer were identified using the National Cancer Database. Institutions treating Black and Hispanic patients in the top decile were categorized as an MSH. Factors associated with the primary outcome of definitive surgical resection were evaluated using multivariable logistic regression. Univariate and multivariable survival analysis was performed. RESULTS: Of the 75,513 patients included in this study, 7.2% were treated at MSH. Patients treated at MSH were younger, more likely to be uninsured, and higher stage compared to those treated at non-MSH (P < 0.001). Patients treated at MSH underwent surgical resection at lower rates (MSH 40% versus non-MSH 44.5%, P < 0.001). On multivariable logistic regression, treatment at MSH was associated with decreased likelihood of undergoing definitive surgery (odds ratio 0.91, P = 0.006). Of those who underwent surgical resection, multivariable survival analysis revealed that treatment at an MSH was associated with increased morality (hazard ratio 1.12, P < 0.001). CONCLUSIONS: Patients with resectable pancreatic adenocarcinoma treated at MSH are less likely to undergo surgical resection compared to those treated at non-MSH. Targeted interventions are needed to address the unique barriers facing MSH facilities in providing care to patients with pancreatic adenocarcinoma.

Diverse African genomes reveal selection on ancient modern human introgressions in Neanderthals.

Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups-a hallmark of incipient speciation.

Piperacillin-Tazobactam Compared With Cefoxitin as Antimicrobial Prophylaxis for Pancreatoduodenectomy: A Randomized Clinical Trial.

Importance: Despite improvements in perioperative mortality, the incidence of postoperative surgical site infection (SSI) remains high after pancreatoduodenectomy. The effect of broad-spectrum antimicrobial surgical prophylaxis in reducing SSI is poorly understood. Objective: To define the effect of broad-spectrum perioperative antimicrobial prophylaxis on postoperative SSI incidence compared with standard care antibiotics. Design, Setting, and Participants: Pragmatic, open-label, multicenter, randomized phase 3 clinical trial at 26 hospitals across the US and Canada. Participants were enrolled between November 2017 and August 2021, with follow-up through December 2021. Adults undergoing open pancreatoduodenectomy for any indication were eligible. Individuals were excluded if they had allergies to study medications, active infections, chronic steroid use, significant kidney dysfunction, or were pregnant or breastfeeding. Participants were block randomized in a 1:1 ratio and stratified by the presence of a preoperative biliary stent. Participants, investigators, and statisticians analyzing trial data were unblinded to treatment assignment. Intervention: The intervention group received piperacillin-tazobactam (3.375 or 4 g intravenously) as perioperative antimicrobial prophylaxis, while the control group received cefoxitin (2 g intravenously; standard care). Main Outcomes and Measures: The primary outcome was development of postoperative SSI within 30 days. Secondary end points included 30-day mortality, development of clinically relevant postoperative pancreatic fistula, and sepsis. All data were collected as part of the American College of Surgeons National Surgical Quality Improvement Program. Results: The trial was terminated at an interim analysis on the basis of a predefined stopping rule. Of 778 participants (378 in the piperacillin-tazobactam group [median age, 66.8 y; 233 {61.6%} men] and 400 in the cefoxitin group [median age, 68.0 y; 223 {55.8%} men]), the percentage with SSI at 30 days was lower in the perioperative piperacillin-tazobactam vs cefoxitin group (19.8% vs 32.8%; absolute difference, -13.0% [95% CI, -19.1% to -6.9%]; P < .001). Participants treated with piperacillin-tazobactam, vs cefoxitin, had lower rates of postoperative sepsis (4.2% vs 7.5%; difference, -3.3% [95% CI, -6.6% to 0.0%]; P = .02) and clinically relevant postoperative pancreatic fistula (12.7% vs 19.0%; difference, -6.3% [95% CI, -11.4% to -1.2%]; P = .03). Mortality rates at 30 days were 1.3% (5/378) among participants treated with piperacillin-tazobactam and 2.5% (10/400) among those receiving cefoxitin (difference, -1.2% [95% CI, -3.1% to 0.7%]; P = .32). Conclusions and Relevance: In participants undergoing open pancreatoduodenectomy, use of piperacillin-tazobactam as perioperative prophylaxis reduced postoperative SSI, pancreatic fistula, and multiple downstream sequelae of SSI. The findings support the use of piperacillin-tazobactam as standard care for open pancreatoduodenectomy. Trial Registration: ClinicalTrials.gov Identifier: NCT03269994.

Whole-genome sequencing reveals a complex African population demographic history and signatures of local adaptation.

We conduct high coverage (>30×) whole-genome sequencing of 180 individuals from 12 indigenous African populations. We identify millions of unreported variants, many predicted to be functionally important. We observe that the ancestors of southern African San and central African rainforest hunter-gatherers (RHG) diverged from other populations >200 kya and maintained a large effective population size. We observe evidence for ancient population structure in Africa and for multiple introgression events from "ghost" populations with highly diverged genetic lineages. Although currently geographically isolated, we observe evidence for gene flow between eastern and southern Khoesan-speaking hunter-gatherer populations lasting until ∼12 kya. We identify signatures of local adaptation for traits related to skin color, immune response, height, and metabolic processes. We identify a positively selected variant in the lightly pigmented San that influences pigmentation in vitro by regulating the enhancer activity and gene expression of PDPK1.

Signatures of Convergent Evolution and Natural Selection at the Alcohol Dehydrogenase Gene Region are Correlated with Agriculture in Ethnically Diverse Africans.

The alcohol dehydrogenase (ADH) family of genes encodes enzymes that catalyze the metabolism of ethanol into acetaldehyde. Nucleotide variation in ADH genes can affect the catalytic properties of these enzymes and is associated with a variety of traits, including alcoholism and cancer. Some ADH variants, including the ADH1B*48His (rs1229984) mutation in the ADH1B gene, reduce the risk of alcoholism and are under positive selection in multiple human populations. The advent of Neolithic agriculture and associated increase in fermented foods and beverages is hypothesized to have been a selective force acting on such variants. However, this hypothesis has not been tested in populations outside of Asia. Here, we use genome-wide selection scans to show that the ADH gene region is enriched for variants showing strong signals of positive selection in multiple Afroasiatic-speaking, agriculturalist populations from Ethiopia, and that this signal is unique among sub-Saharan Africans. We also observe strong selection signals at putatively functional variants in nearby lipid metabolism genes, which may influence evolutionary dynamics at the ADH region. Finally, we show that haplotypes carrying these selected variants were introduced into Northeast Africa from a West-Eurasian source within the last ∼2,000 years and experienced positive selection following admixture. These selection signals are not evident in nearby, genetically similar populations that practice hunting/gathering or pastoralist subsistence lifestyles, supporting the hypothesis that the emergence of agriculture shapes patterns of selection at ADH genes. Together, these results enhance our understanding of how adaptations to diverse environments and diets have influenced the African genomic landscape.

Management of Clinical T2N0 Esophageal and Gastroesophageal Junction Adenocarcinoma: What Is the Optimal Treatment?

BACKGROUND: The current standard of care for locally advanced esophageal and gastroesophageal junction (GEJ) adenocarcinoma includes neoadjuvant chemoradiation and surgery. The optimal treatment for clinical T2N0M0 (cT2N0) disease is debated. This study aims to determine the optimal treatment in these patients. METHODS: The National Cancer Database was used to identify patients who underwent surgery for cT2N0 esophageal and GEJ adenocarcinoma from 2004 to 2017. Patients were grouped into surgery-alone, neoadjuvant therapy (NAT), and adjuvant therapy (AT) groups. Subgroups of high-risk patients (tumor ≥ 3 cm, poor differentiation, or lymphovascular invasion) and patients upstaged after upfront surgery were identified. Kaplan-Meier method and Cox proportional hazard ratios were used to compare overall survival. RESULTS: Of 2160 patients included, 957 (44.3%) underwent surgery-alone, 821 (38.0%) underwent NAT and surgery, and 382 (17.7%) underwent surgery and AT. One thousand six hundred nineteen (75.0%) patients had high-risk features. Six hundred fourteen (45.9%) patients were upstaged after upfront surgery. In the overall cohort, AT was associated with improved survival compared to NAT (HR 0.618, p < 0.001) and surgery-alone (HR 0.699, p < 0.001). There was no difference in survival between NAT and surgery-alone (HR 1.132, p = 0.112). Similar results were observed in high-risk patients. Patients upstaged after upfront surgery who received AT had improved survival compared to those initially treated with NAT (HR 0.613, p < 0.001). CONCLUSION: This analysis suggests that cT2N0 esophageal and GEJ adenocarcinomas may not benefit from the intensive multimodality therapy utilized in locally advanced disease. Selective use of AT for patients who are upstaged pathologically, or have high-risk features, is associated with improved outcomes.

Contiguously hydrophobic sequences are functionally significant throughout the human exome.

Hydrophobic interactions have long been established as essential for stabilizing struc-tured proteins as well as drivers of aggregation, but the impact of hydrophobicity on thefunctional significance of sequence variants has rarely been considered in a genome-wide context. Here we test the role of hydrophobicity on functional impact across70,000 disease- and non­disease-associated single-nucleotide polymorphisms (SNPs),using enrichment of disease association as an indicator of functionality. We find thatfunctional impact is uncorrelated with hydrophobicity of the SNP itself and only weaklycorrelated with the average local hydrophobicity, but is strongly correlated with boththe size and minimum hydrophobicity of the contiguously hydrophobic sequence (or"blob") that contains the SNP. Disease association is found to vary by more than sixfoldas a function of contiguous hydrophobicity parameters, suggesting utility as a prior foridentifying causal variation. We further find signatures of differential selective constrainton hydrophobic blobs and that SNPs splitting a long hydrophobic blob or joiningtwo short hydrophobic blobs are particularly likely to be disease associated. Trends arepreserved for both aggregating and nonaggregating proteins, indicating that the role ofcontiguous hydrophobicity extends well beyond aggregation risk.

Is preoperative biliary stenting associated with increased rate of postoperative complications for patients undergoing pancreatoduodenectomy? A review of national surgical quality improvement program data.

BACKGROUND: Jaundice in the setting of periampullary neoplasms is often treated with biliary stenting. Level 1 data demonstrated an increase in perioperative complications after pancreaticoduodenectomy in patients undergoing stent placement. However, the impact of this data on practice patterns in the US remains unknown. METHODS: The National Surgical Quality Improvement Program (NSQIP) Pancreatectomy Targeted Participant Use Data File was used to identify patients from 2014 to 2017 undergoing pancreatoduodenectomy. Chi-square test and multivariable logistic regression were used to compare outcomes between those with biliary stent and those without. RESULTS: Of the 5524 patients, 3321 (60.1%) had biliary stent placement. The stent group was older, had a higher ASA class, and had preoperative weight loss compared to the group without biliary stenting (all p < 0.05). When adjusting for demographic and operative characteristics, the non-stent group had lower associated overall complications and postoperative infections. There was no significant difference in mortality and pancreatic fistula rate between groups. CONCLUSION: Preoperative biliary stenting is still common prior to pancreaticoduodenectomy. With a trend toward increased utilization of neoadjuvant chemotherapy, stenting will likely remain a common practice. Recognition of increased rates of complications associated with stent placement allows for appropriate risk-benefit analysis.

Convergent evolution of bacterial ceramide synthesis.

The bacterial domain produces numerous types of sphingolipids with various physiological functions. In the human microbiome, commensal and pathogenic bacteria use these lipids to modulate the host inflammatory system. Despite their growing importance, their biosynthetic pathway remains undefined since several key eukaryotic ceramide synthesis enzymes have no bacterial homolog. Here we used genomic and biochemical approaches to identify six proteins comprising the complete pathway for bacterial ceramide synthesis. Bioinformatic analyses revealed the widespread potential for bacterial ceramide synthesis leading to our discovery of a Gram-positive species that produces ceramides. Biochemical evidence demonstrated that the bacterial pathway operates in a different order from that in eukaryotes. Furthermore, phylogenetic analyses support the hypothesis that the bacterial and eukaryotic ceramide pathways evolved independently.

Advances in integrative African genomics.

There has been a rapid increase in human genome sequencing in the past two decades, resulting in the identification of millions of previously unknown genetic variants. However, African populations are under-represented in sequencing efforts. Additional sequencing from diverse African populations and the construction of African-specific reference genomes is needed to better characterize the full spectrum of variation in humans. However, sequencing alone is insufficient to address the molecular and cellular mechanisms underlying variable phenotypes and disease risks. Determining functional consequences of genetic variation using multi-omics approaches is a fundamental post-genomic challenge. We discuss approaches to close the knowledge gaps about African genomic diversity and review advances in African integrative genomic studies and their implications for precision medicine.

Undertreatment of Pancreatic Cancer: The Intersection of Bias, Biology, and Geography.

Pancreatic cancer is the third leading cause of cancer deaths in the United States. Black patients with pancreatic cancer experience higher incidence and increased mortality. Although racial biologic differences exist, socioeconomic status, insurance type, physician bias, and patient beliefs contribute to the disparities in outcomes observed among patients who are Black, indigenous, and people of color.

Endoscopic hemostatic spray for uncontrolled bleeding after complicated endoscopic mucosal resection or endoscopic submucosal dissection: a report of 2 cases.

BACKGROUND AND AIMS: There is a significant bleeding risk after gastric endoscopic submucosal dissection (ESD) and EMR cases. This case series describes the use of an endoscopic hemostasis spray, which is not typically used to treat this type of bleeding, after multiple attempts with other modalities failed. METHODS: We present 2 patient cases of ESD and EMR used to treat a gastric adenoma (case 1) and 2 gastric hyperplastic masses (case 2) with refractory bleeding after use of multiple other treatment modalities. Both patients were not surgical candidates because of their medical comorbidities. RESULTS: Bleeding was eventually controlled with the use of endoscopic hemostasis spray after attempts were made using SB Knife Jr tip, Coagrasper Hemostatic Forceps, Argon Photocoagulation, and scope tamponade. CONCLUSIONS: In very specific cases, endoscopic hemostasis spray may have some utility for refractory bleeding after dissection of gastric lesions. After using this spray, it became technically challenging to suture endoscopically because of the mud-like quality of the hemostasis material.

Pathologic upstaging in resected pancreatic adenocarcinoma: Risk factors and impact on survival.

BACKGROUND: Clinical and pathologic staging determine treatment of pancreatic cancer. Clinical stage has been shown to underestimate final pathologic stage in pancreatic cancer, resulting in upstaging. METHODS: National Cancer Database was used to identify clinical stage I pancreatic adenocarcinoma. Univariate, multivariable logistic regression, and Cox proportional hazard ratio were used to determine differences between upstaged and stage concordant patients. RESULTS: Upstaging was seen in 80.2% of patients. Factors found to be significantly associated with upstaging included pancreatic head tumors (OR 2.56), high-grade histology (OR 1.74), elevated Ca 19-9 (OR 2.09), and clinical stage T2 (OR 1.99). Upstaging was associated with a 45% increased risk of mortality compared to stage concordant disease (HR 1.44, p < .001). CONCLUSION: A majority of clinical stage I pancreatic cancer is upstaged after resection. Factors including tumor location, grade, Ca 19-9, and tumor size can help identify those at high risk for upstaging.

Admixture/fine-mapping in Brazilians reveals a West African associated potential regulatory variant (rs114066381) with a strong female-specific effect on body mass and fat mass indexes.

BACKGROUND/OBJECTIVES: Admixed populations are a resource to study the global genetic architecture of complex phenotypes, which is critical, considering that non-European populations are severely underrepresented in genomic studies. Here, we study the genetic architecture of BMI in children, young adults, and elderly individuals from the admixed population of Brazil. SUBJECTS/METHODS: Leveraging admixture in Brazilians, whose chromosomes are mosaics of fragments of Native American, European, and African origins, we used genome-wide data to perform admixture mapping/fine-mapping of body mass index (BMI) in three Brazilian population-based cohorts from Northeast (Salvador), Southeast (Bambuí), and South (Pelotas). RESULTS: We found significant associations with African-associated alleles in children from Salvador (PALD1 and ZMIZ1 genes), and in young adults from Pelotas (NOD2 and MTUS2 genes). More importantly, in Pelotas, rs114066381, mapped in a potential regulatory region, is significantly associated only in females (p = 2.76e-06). This variant is rare in Europeans but with frequencies of ~3% in West Africa and has a strong female-specific effect (95% CI: 2.32-5.65 kg/m2 per each A allele). We confirmed this sex-specific association and replicated its strong effect for an adjusted fat mass index in the same Pelotas cohort, and for BMI in another Brazilian cohort from São Paulo (Southeast Brazil). A meta-analysis confirmed the significant association. Remarkably, we observed that while the frequency of rs114066381-A allele ranges from 0.8 to 2.1% in the studied populations, it attains ~9% among women with morbid obesity from Pelotas, São Paulo, and Bambuí. The effect size of rs114066381 is at least five times higher than the FTO SNPs rs9939609 and rs1558902, already emblematic for their high effects. CONCLUSIONS: We identified six candidate SNPs associated with BMI. rs114066381 stands out for its high effect that was replicated and its high frequency in women with morbid obesity. We demonstrate how admixed populations are a source of new relevant phenotype-associated genetic variants.