Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
1.
Ann Neurol ; 93(5): 893-905, 2023 05.
Article in English | MEDLINE | ID: mdl-36602053

ABSTRACT

OBJECTIVE: Monkeypox virus (MPXV) disease has been declared a public health emergency by the World Health Organization, creating an urgent need for neurologists to be able to recognize, diagnosis, and treat MPXV-associated neurologic disease. METHODS: Three cases of MPXV-associated central nervous system (CNS) disease occurring during the 2022 outbreak, and their associated imaging findings are presented, with 2 cases previously published in a limited capacity in a public health bulletin. RESULTS: Three previously healthy immunocompetent gay men in their 30s developed a febrile illness followed by progressive neurologic symptoms with presence of a vesiculopustular rash. MPXV nucleic acid was detected by polymerase chain reaction (PCR) from skin lesions of 2 patients, with the third patient having indeterminate testing but an epidemiologic link to a confirmed MPXV disease case. Cerebrospinal fluid demonstrated a lymphocytic pleocytosis, elevated protein, and negative MPXV-specific PCR. In 2 patients, magnetic resonance imaging of the brain and spine demonstrated partially enhancing, longitudinally extensive central spinal cord lesions with multifocal subcortical, basal ganglia, thalamic, cerebellar, and/or brainstem lesions. The third patient had thalamic and basal ganglia lesions. All patients received 14 days of tecovirimat, and 2 patients also received multiple forms of immunotherapy, including intravenous immunoglobulin, pulsed high-dose steroids, plasmapheresis, and/or rituximab. Good neurologic recovery was observed in all cases. INTERPRETATION: MPXV can be associated with CNS disease. It is unclear whether this is from a parainfectious immune-mediated injury or direct CNS viral invasion. ANN NEUROL 2023;93:893-905.


Subject(s)
Central Nervous System Diseases , Mpox (monkeypox) , Humans , Male , Central Nervous System Diseases/virology , Magnetic Resonance Imaging , Mpox (monkeypox)/diagnosis , Mpox (monkeypox)/pathology , Monkeypox virus/physiology
2.
Am J Trop Med Hyg ; 107(2): 315-319, 2022 08 17.
Article in English | MEDLINE | ID: mdl-35895583

ABSTRACT

We used a protein microarray featuring Plasmodium falciparum field variants of a merozoite surface antigen to examine malaria exposure in Malian children with different severe malaria syndromes. Unlike children with cerebral malaria alone or severe malarial anemia alone, those with concurrent cerebral malaria and severe malarial anemia had serologic responses demonstrating a broader prior parasite exposure pattern than matched controls with uncomplicated disease. Comparison of levels of malaria-related cytokines revealed that children with the concurrent phenotype had elevated levels of interleukin (IL)-6, IL-8, and IL-10. Our results suggest that the pathophysiology of this severe subtype is unique and merits further investigation.


Subject(s)
Anemia , Malaria, Cerebral , Malaria, Falciparum , Humans , Malaria, Cerebral/complications , Plasmodium falciparum , Cytokines , Anemia/etiology , Interleukin-6
3.
J Infect Dis ; 224(4): 695-704, 2021 08 16.
Article in English | MEDLINE | ID: mdl-33400784

ABSTRACT

BACKGROUND: Tuberculosis (TB) is the most deadly infectious disease globally and is highly prevalent in the developing world. For individuals infected with both Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV), the risk of active TB is 10% or more annually. Previously, we identified in a genome-wide association study (GWAS) a region on chromosome 5 associated with resistance to TB, which included epigenetic marks that could influence gene regulation. We hypothesized that HIV-infected individuals exposed to Mtb who remain disease free carry epigenetic changes that strongly protect them from active TB. METHODS: We conducted a methylome-wide study in HIV-infected, TB-exposed cohorts from Uganda and Tanzania and integrated data from our GWAS. RESULTS: We identified 3 regions of interest that included markers that were differentially methylated between TB cases and controls with latent TB infection: chromosome 1 (RNF220, P = 4 × 10-5), chromosome 2 (between COPS8 and COL6A3, P = 2.7 × 10-5), and chromosome 5 (CEP72, P = 1.3 × 10-5). These methylation results co-localized with associated single-nucleotide polymorphisms (SNPs), methylation QTLs, and methylation × SNP interaction effects. These markers were in regions with regulatory markers for cells involved in TB immunity and/or lung. CONCLUSIONS: Epigenetic regulation is a potential biologic factor underlying resistance to TB in immunocompromised individuals that can act in conjunction with genetic variants.


Subject(s)
Disease Resistance/genetics , Epigenesis, Genetic , Epigenome , HIV Infections , Tuberculosis , Biomarkers , Genome-Wide Association Study , HIV , HIV Infections/complications , HIV Infections/genetics , Humans , Tanzania , Tuberculosis/genetics , Uganda
4.
Infect Genet Evol ; 85: 104560, 2020 11.
Article in English | MEDLINE | ID: mdl-32971250

ABSTRACT

Tuberculosis (TB) is the leading cause of death from a single infectious agent. According to the WHO, 85% of cases in 2018 were pulmonary tuberculosis (PTB), making it the most prevalent form of the disease. Although the bacillus responsible for disease, Mycobacterium tuberculosis (MTB), is estimated to infect 1.7 billion people worldwide, only a small portion of those infected (5-10%) will transition into active TB. Because such a small fraction of infected people develop active disease, we hypothesized that underlying host genetic variation associates with developing active pulmonary disease. Variation in CLEC4E has been of interest in previous association studies showing either no effect or protection from PTB. For our study we assessed 60 SNPs in 11 immune genes, including CLEC4E, using a case-control study from Guinea-Bissau. The 289 cases and 322 controls differed in age, sex, and ethnicity all of which were included in adjusted models. Initial association analysis with unadjusted logistic regression revealed putative association with seven SNPs (p < 0.05). All SNPs were then assessed in an adjusted model. Of the six SNPs that remained significant, three of them were assigned to the CLEC4E gene (rs12302046, rs10841847, and rs11046143). Of these, only rs10841847 passed FDR adjustment for multiple testing. Adjusted regression analyses showed that the minor allele at rs10841847 associated with higher risk of developing PTB (OR = 1.55, CI = 1.22-1.96, p-value = 0.00036). Based on these initial association tests, CLEC4E seemed to be the predictor of interest for PTB risk in this population. Haplotype analysis (2-SNP and 3-SNP windows) showed that minor alleles in segments including rs10841847 were the only ones to pass the threshold of global significance, compared to other haplotypes (p-value < 0.05). Linkage disequilibrium patterns showed that rs12302046 is in high LD with rs10841847 (r2 = 0.67), and all other SNPs lost significance when adjusted for rs10841847 effects. These findings indicate that rs10841847 in CLEC4E is the single best predictor of pulmonary tuberculosis risk in our study population. These results provide evidence for the hypothesis that genetic variation of CLEC4E influences risk to TB in Guinea-Bissau.


Subject(s)
Genetic Predisposition to Disease , Genetic Variation , Lectins, C-Type/genetics , Receptors, Immunologic/genetics , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/etiology , Alleles , Case-Control Studies , Guinea-Bissau/epidemiology , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Linkage Disequilibrium , Mycobacterium tuberculosis , Polymorphism, Single Nucleotide , Public Health Surveillance , Risk Assessment , Tuberculosis, Pulmonary/diagnosis
5.
PLoS Genet ; 13(6): e1006710, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28628665

ABSTRACT

One in three people has been infected with Mycobacterium tuberculosis (MTB), and the risk for MTB infection in HIV-infected individuals is even higher. We hypothesized that HIV-positive individuals living in tuberculosis-endemic regions who do not get infected by Mycobacterium tuberculosis are genetically resistant. Using an "experiment of nature" design that proved successful in our previous work, we performed a genome-wide association study of tuberculin skin test positivity using 469 HIV-positive patients from prospective study cohorts of tuberculosis from Tanzania and Uganda to identify genetic loci associated with MTB infection in the context of HIV-infection. Among these individuals, 244 tested were tuberculin skin test (TST) positive either at enrollment or during the >8 year follow up, while 225 were not. We identified a genome-wide significant association between a dominant model of rs877356 and binary TST status in the combined cohort (Odds ratio = 0.2671, p = 1.22x10-8). Association was replicated with similar significance when examining TST induration as a continuous trait. The variant lies in the 5q31.1 region, 57kb downstream from IL9. Two-locus analyses of association of variants near rs877356 showed a haplotype comprised of rs877356 and an IL9 missense variant, rs2069885, had the most significant association (p = 1.59x10-12). We also replicated previously linked loci on chromosomes 2, 5, and 11. IL9 is a cytokine produced by mast cells and TH2 cells during inflammatory responses, providing a possible link between airway inflammation and protection from MTB infection. Our results indicate that studying uninfected, HIV-positive participants with extensive exposure increases the power to detect associations in complex infectious disease.


Subject(s)
Chromosomes, Human, Pair 5/genetics , Genome-Wide Association Study , HIV Infections/genetics , Tuberculosis/genetics , Adult , Endemic Diseases , Female , HIV/genetics , HIV/pathogenicity , HIV Infections/complications , HIV Infections/microbiology , HIV Infections/virology , Haplotypes/genetics , Humans , Male , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/pathogenicity , Skin Tests , Tanzania , Tuberculin Test , Tuberculosis/complications , Tuberculosis/microbiology , Tuberculosis/virology , Uganda
6.
Genome Announc ; 5(15)2017 Apr 13.
Article in English | MEDLINE | ID: mdl-28408665

ABSTRACT

We present here the draft genomes of 13 Helicobacter pylori strains isolated from Colombian residents on the Pacific coast (n = 6) and in the Andes mountains (n = 7), locations that differ in gastric cancer risk. These 13 strains were obtained from individuals with diagnosed gastric lesions.

7.
Glob Heart ; 12(2): 133-140, 2017 06.
Article in English | MEDLINE | ID: mdl-28408189

ABSTRACT

Plasma concentration of plasminogen activator inhibitor-1 (PAI-1) is highly correlated with several cardiovascular disease (CVD) risk factors. It also plays a direct role in CVD, including myocardial infarction and stroke, by impeding the dissolution of thrombi in the blood. Insofar as PAI-1 links CVD's risk factors to its endpoints, genetic variants modulating the relationship between PAI-1 and risk factors may be of particular clinical and biological interest. The high heritability of PAI-1, which has not been explained by genetic association studies, may also, in large part, be due to this relationship with CVD risk factors. Using exome-wide data from 1,032 Ghanaian study participants, we tested for heterogeneity of correlation by genotype between PAI-1 and 4 CVD risk factors (body mass index, triglycerides, mean arterial pressure, and fasting glucose) under the hypothesis that loci involved in the relationship between PAI-1 and other risk factors will also modify their correlational structure. We found more significant heterogeneities of correlation by genotype than we found marginal effects, with no evidence of type I inflation. The most significant result among all univariate and multivariate tests performed in this study was the heterogeneity of correlation between PAI-1 and mean arterial pressure at rs10738554, near SLC24A2, a gene previously associated with high blood pressure in African Americans.


Subject(s)
Cardiovascular Diseases/genetics , DNA/genetics , Plasminogen Activator Inhibitor 1/genetics , Polymorphism, Single Nucleotide , Risk Assessment , Cardiovascular Diseases/epidemiology , Exome , Genotype , Ghana/epidemiology , Humans , Morbidity/trends , Plasminogen Activator Inhibitor 1/metabolism , Risk Factors
8.
Curr Genet Med Rep ; 5(4): 149-166, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29805915

ABSTRACT

PURPOSE OF REVIEW: Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), remains a major public health threat globally. Several lines of evidence support a role for host genetic factors in resistance/susceptibility to TB disease and MTB infection. However, results across candidate gene and genome-wide association studies (GWAS) are largely inconsistent, so a cohesive genetic model underlying TB risk has not emerged. RECENT FINDINGS: Despite the difficulties in identifying consistent genetic associations, genetic studies of TB and MTB infection have revealed a few well-documented loci. These well validated genes are presented in this review, but there remains a large gap in how these genes translate into better understanding of TB. To address this, we present a pathway based extension of standard association analyses, seeding the results with the best validated genes from candidate gene and GWAS studies. SUMMARY: Several pathways were significantly enriched using pathway analyses that may help to explain population patterns of TB risk. In conclusion, we advocate for novel approaches to the study of host genetic analysis of TB that extend traditional association approaches.

9.
J Am Heart Assoc ; 5(10)2016 10 03.
Article in English | MEDLINE | ID: mdl-27697752

ABSTRACT

BACKGROUND: Metabolic syndrome (MetS) is diagnosed by the presence of at least 3 of the following: obesity, hypertension, hyperglycemia, hypertriglyceridemia, and low high-density lipoprotein. Individuals with MetS also typically have elevated plasma levels of the antifibrinolytic factor, plasminogen activator inhibitor-1 (PAI-1), but the relationships between PAI-1 and MetS diagnostic criteria are not clear. Understanding these relationships can elucidate the relevance of MetS to cardiovascular disease risk, because PAI-1 is associated with ischemic events and directly involved in thrombosis. METHODS AND RESULTS: In a cross-sectional analysis of 2220 Ghanaian men and women from urban and rural locales, we found the age-standardized prevalence of MetS to be as high as 21.4% (urban women). PAI-1 level increased exponentially as the number of diagnostic criteria increased linearly (P<10-13), supporting the conclusion that MetS components have a joint effect that is stronger than their additive contributions. Body mass index, triglycerides, and fasting glucose were more strongly correlated with PAI-1 than with canonical MetS criteria, and this pattern did not change when pair-wise correlations were conditioned on all other risk factors, supporting an independent role for PAI-1 in MetS. Finally, whereas the correlations between conventional risk factors did not vary significantly by sex or across urban and rural environments, correlations with PAI-1 were generally stronger among urban participants. CONCLUSIONS: MetS prevalence in the West African population we studied was comparable to that of the industrialized West. PAI-1 may serve as a key link between MetS, as currently defined, and the endpoints with which it is associated. Whether this association is generalizable will require follow-up.


Subject(s)
Metabolic Syndrome/blood , Plasminogen Activator Inhibitor 1/blood , Adolescent , Adult , Antihypertensive Agents/therapeutic use , Blood Glucose/metabolism , Blood Pressure , Body Mass Index , Cholesterol, HDL/blood , Cross-Sectional Studies , Diabetes Mellitus/drug therapy , Diabetes Mellitus/epidemiology , Fasting , Female , Ghana/epidemiology , Humans , Hypertension/drug therapy , Hypertension/epidemiology , Hypoglycemic Agents/therapeutic use , Male , Metabolic Syndrome/epidemiology , Middle Aged , Prevalence , Rural Population/statistics & numerical data , Triglycerides/blood , Urban Population/statistics & numerical data , Young Adult
10.
PLoS One ; 11(10): e0162753, 2016.
Article in English | MEDLINE | ID: mdl-27732601

ABSTRACT

Populations in sub-Saharan Africa are shifting from rural to increasingly urban. Although the burden of cardiovascular disease is expected to increase with this changing landscape, few large studies have assessed a wide range of risk factors in urban and rural populations, particularly in West Africa. We conducted a cross-sectional, population-based survey of 3317 participants from Ghana (≥18 years old), of whom 2265 (57% female) were from a mid-sized city (Sunyani, population ~250,000) and 1052 (55% female) were from surrounding villages (populations <5000). We measured canonical cardiovascular disease risk factors (BMI, blood pressure, fasting glucose, lipids) and fibrinolytic markers (PAI-1 and t-PA), and assessed how their distributions and related clinical outcomes (including obesity, hypertension and diabetes) varied with urban residence and sex. Urban residence was strongly associated with obesity (OR: 7.8, 95% CI: 5.3-11.3), diabetes (OR 3.6, 95% CI: 2.3-5.7), and hypertension (OR 3.2, 95% CI: 2.6-4.0). Among the quantitative measures, most affected were total cholesterol (+0.81 standard deviations, 95% CI 0.73-0.88), LDL cholesterol (+0.89, 95% CI: 0.79-0.99), and t-PA (+0.56, 95% CI: 0.48-0.63). Triglycerides and HDL cholesterol profiles were similarly poor in both urban and rural environments, but significantly worse among rural participants after BMI-adjustment. For most of the risk factors, the strength of the association with urban residence did not vary with sex. Obesity was a major exception, with urban women at particularly high risk (26% age-standardized prevalence) compared to urban men (7%). Overall, urban residents had substantially worse cardiovascular risk profiles, with some risk factors at levels typically seen in the developed world.


Subject(s)
Cardiovascular Diseases/etiology , Urbanization , Adolescent , Adult , Aged , Aged, 80 and over , Blood Glucose/analysis , Blood Pressure , Body Mass Index , Cardiovascular Diseases/epidemiology , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Cross-Sectional Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/epidemiology , Female , Ghana/epidemiology , Humans , Hypertension/complications , Hypertension/epidemiology , Male , Middle Aged , Obesity/complications , Obesity/epidemiology , Plasminogen Activator Inhibitor 1/blood , Prevalence , Risk Factors , Smoking , Surveys and Questionnaires , Tissue Plasminogen Activator/blood , Triglycerides/blood , Young Adult
12.
Hum Genet ; 135(8): 895-906, 2016 08.
Article in English | MEDLINE | ID: mdl-27225266

ABSTRACT

Gastric cancer incidence varies considerably among populations, even those with comparable rates of Helicobacter pylori infection. To test the hypothesis that genetic variation plays a role in gastric disease, we assessed the relationship between genotypes and gastric histopathology in a Colombian study population, using a genotyping array of immune-related single nucleotide polymorphisms (SNPs). Two synonymous SNPs (rs6061243 and rs6587239) were associated with progression of premalignant gastric lesions in a dominant-effects model after correction for multiple comparisons (p = 2.63E-07 and p = 7.97E-07, respectively); effect sizes were ß = -0.863 and ß = -0.815, respectively, where ß is an estimate of effect on histopathology scores, which ranged from 1 (normal) to 5 (dysplasia). In our replication cohort, a second Colombian population, both SNPs were associated with histopathology when additively modeled (ß = -0.256, 95 % CI = -0.47, -0.039; and ß = -0.239, 95 % CI = -0.45, -0.024), and rs6587239 was significantly associated in a dominant-effects model (ß = -0.330, 95 % CI = -0.66, 0.00). Because promoter methylation of GATA5 has previously been associated with gastric cancer, we also tested for the association of methylation status with more advanced histopathology scores in our samples and found a significant relationship (p = 0.001). A multivariate regression model revealed that the effects of both the promoter methylation and the exonic SNPs in GATA5 were independent. A SNP-by-methylation interaction term was also significant. This interaction between GATA5 variants and GATA5 promoter methylation indicates that the association of either factor with gastric disease progression is modified by the other.


Subject(s)
DNA Methylation/genetics , Epigenomics , GATA5 Transcription Factor/genetics , Helicobacter Infections/genetics , Stomach Neoplasms/genetics , Adult , Female , Genetic Association Studies , Genotype , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Helicobacter pylori/pathogenicity , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Promoter Regions, Genetic , Risk Factors , Stomach Neoplasms/microbiology , Stomach Neoplasms/pathology
13.
Malar J ; 15: 150, 2016 Mar 09.
Article in English | MEDLINE | ID: mdl-26961973

ABSTRACT

BACKGROUND: The host response to infection by Plasmodium falciparum, the parasite most often responsible for severe malaria, ranges from asymptomatic parasitaemia to death. The clinical trajectory of malaria is influenced by host genetics and parasite load, but the factors determining why some infections produce uncomplicated malaria and some proceed to severe disease remain incompletely understood. METHODS: To identify molecular markers of severe falciparum malaria, human gene expression patterns were compared between children aged 6 months to 5 years with severe and uncomplicated malaria who were enrolled in a case-control study in Bandiagara, Mali. Microarrays were used to obtain expression data on severe cases and uncomplicated controls at the time of acute disease presentation (five uncomplicated and five severe), 1 week after presentation (three uncomplicated and three severe) and treatment initiation, and in the subsequent dry season (late convalescence, four uncomplicated and four severe). This is a pilot study for the first use of microarray technology in Mali. RESULTS: Complement and toll-like receptor (TLR) pathways were differentially expressed, with severe cases showing higher expression of the C1q, TLR2, TLR4, TLR8, and CR1 genes. Other genes previously associated with malaria pathogenesis, GZMB, FOS and HSPA6, were also higher among severe cases. TLR2, TLR4, TLR8, CR1, GZMB, FOS, and HSPA6 genes were expressed at lower levels in severe cases at late convalescence. CONCLUSIONS: Overexpression of genes previously associated with uncomplicated malaria was associated with severe disease. Low baseline expression of these genes may represent candidate markers for severe malaria. Despite the small sample size, results of this pilot study offer promising targets for follow-up analyses.


Subject(s)
Complement System Proteins/genetics , Malaria, Falciparum/epidemiology , Malaria, Falciparum/genetics , Toll-Like Receptors/genetics , Biomarkers/metabolism , Case-Control Studies , Child, Preschool , Cluster Analysis , Complement System Proteins/metabolism , Female , Gene Expression Profiling , Humans , Infant , Malaria, Falciparum/metabolism , Malaria, Falciparum/physiopathology , Male , Mali , Molecular Epidemiology , Oligonucleotide Array Sequence Analysis , Pilot Projects , Plasmodium falciparum , Toll-Like Receptors/metabolism
14.
Am J Hum Genet ; 98(3): 514-524, 2016 Mar 03.
Article in English | MEDLINE | ID: mdl-26942285

ABSTRACT

Immunosuppression resulting from HIV infection increases the risk of progression to active tuberculosis (TB) both in individuals newly exposed to Mycobacterium tuberculosis (MTB) and in those with latent infections. We hypothesized that HIV-positive individuals who do not develop TB, despite living in areas where it is hyperendemic, provide a model of natural resistance. We performed a genome-wide association study of TB resistance by using 581 HIV-positive Ugandans and Tanzanians enrolled in prospective cohort studies of TB; 267 of these individuals developed active TB, and 314 did not. A common variant, rs4921437 at 5q33.3, was significantly associated with TB (odds ratio = 0.37, p = 2.11 × 10(-8)). This variant lies within a genomic region that includes IL12B and is embedded in an H3K27Ac histone mark. The locus also displays consistent patterns of linkage disequilibrium across African populations and has signals of strong selection in populations from equatorial Africa. Along with prior studies demonstrating that therapy with IL-12 (the cytokine encoded in part by IL12B, associated with longer survival following MTB infection in mice deficient in CD4 T cells), our results suggest that this pathway might be an excellent target for the development of new modalities for treating TB, especially for HIV-positive individuals. Our results also indicate that studying extreme disease resistance in the face of extensive exposure can increase the power to detect associations in complex infectious disease.


Subject(s)
Genetic Loci , Genetic Predisposition to Disease , Interleukin-12 Subunit p40/genetics , Tuberculosis/genetics , Adolescent , Female , Gene Frequency , Genome-Wide Association Study , HIV Infections/microbiology , Humans , Interleukin-12 Subunit p40/metabolism , Linkage Disequilibrium , Logistic Models , Male , Mycobacterium tuberculosis , Prospective Studies , Risk Factors , Tanzania , Tuberculosis/diagnosis , Uganda
15.
J Am Heart Assoc ; 4(7)2015 Jun 30.
Article in English | MEDLINE | ID: mdl-26126546

ABSTRACT

BACKGROUND: Plasma lipid levels are highly heritable traits, but known genetic loci can only explain a small portion of their heritability. METHODS AND RESULTS: In this study, we analyzed the role of parental levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) in explaining the values of the corresponding traits in adult offspring. We also evaluated the contribution of nongenetic factors that influence lipid traits (age, body mass index, smoking, medications, and menopause) alone and in combination with variability at the genetic loci known to associate with TC, LDL-C, HDL-C, and TG levels. We performed comparisons among different sex-specific regression models in 416 families from the Framingham Heart Study and 304 from the SardiNIA cohort. Models including parental lipid levels explain significantly more of the trait variation than models without these measures, explaining up to ≈39% of the total trait variation. Of this variation, the parent-of-origin effect explains as much as ≈15% and it does so in a sex-specific way. This observation is not owing to shared environment, given that spouse-pair correlations were negligible (<1.5% explained variation in all cases) and is distinct from previous genetic and acquired factors that are known to influence serum lipid levels. CONCLUSIONS: These findings support the concept that unknown genetic and epigenetic contributors are responsible for most of the heritable component of the plasma lipid phenotype, and that, at present, the clinical utility of knowing age-matched parental lipid levels in assessing risk of dyslipidemia supersedes individual locus effects. Our results support the clinical utility of knowing parental lipid levels in assessing future risk of dyslipidemia.


Subject(s)
Adult Children , Dyslipidemias/genetics , Fathers , Lipid Metabolism/genetics , Lipids/blood , Mothers , Adult , Biomarkers/blood , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Dyslipidemias/blood , Dyslipidemias/diagnosis , Dyslipidemias/epidemiology , Female , Gene-Environment Interaction , Genetic Predisposition to Disease , Heredity , Humans , Italy/epidemiology , Male , Massachusetts/epidemiology , Middle Aged , Models, Biological , Pedigree , Phenotype , Risk Factors , Sex Factors , Triglycerides/blood
16.
Ann Hum Genet ; 79(2): 136-47, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25644736

ABSTRACT

The number of effectively independent tests performed in genome-wide association studies (GWAS) varies by population, making a universal P-value threshold inappropriate. We estimated the number of independent SNPs in Phase 3 HapMap samples by: (1) the LD-pruning function in PLINK, and (2) an autocorrelation-based approach. Autocorrelation was also used to estimate the number of independent SNPs in whole genome sequences from 1000 Genomes. Both approaches yielded consistent estimates of numbers of independent SNPs, which were used to calculate new population-specific thresholds for genome-wide significance. African populations had the most stringent thresholds (1.49 × 10(-7) for YRI at r(2) = 0.3), East Asian populations the least (3.75 × 10(-7) for JPT at r(2) = 0.3). We also assessed how using population-specific significance thresholds compared to using a single multiple testing threshold at the conventional 5 × 10(-8) cutoff. Applied to a previously published GWAS of melanoma in Caucasians, our approach identified two additional genes, both previously associated with the phenotype. In a Chinese breast cancer GWAS, our approach identified 48 additional genes, 19 of which were in or near genes previously associated with the phenotype. We conclude that the conventional genome-wide significance threshold generates an excess of Type 2 errors, particularly in GWAS performed on more recently founded populations.


Subject(s)
Genome-Wide Association Study , HapMap Project , Melanoma/genetics , Asian People/genetics , Genetics, Population , Humans , Polymorphism, Single Nucleotide , White People/genetics
17.
BMC Infect Dis ; 14: 542, 2014 Oct 09.
Article in English | MEDLINE | ID: mdl-25300708

ABSTRACT

BACKGROUND: Aminoglycosides are a critical component of multidrug-resistant tuberculosis (MDR-TB) treatment but data on their efficacy and adverse effects in Botswana is scarce. We determined the effect of amikacin on treatment outcomes and development of hearing loss in MDR-TB patients. METHODS: Patients started on MDR-TB treatment between 2006 and 2012 were included. Multivariate analysis was used to determine the effect of amikacin on treatment outcomes and development of hearing loss. RESULTS: 437 MDR-TB patients were included, 288 (66%) of whom were HIV co-infected. 270 (62%) developed hearing loss, of whom 147 (54%) had audiometry. Of the 313 (72%) patients who completed treatment, 228 (73%) had a good outcome (cure or treatment completion). Good outcome was associated with longer amikacin treatment (adjusted OR [aOR] 1.13, 95% CI 1.06 - 1.21) and higher dosage (aOR 1.90, 95% CI 1.12 - 2.99). Longer amikacin duration (aOR 1.98, 95% CI 1.86 - 2.12) and higher dosage per weight per month (aOR 1.15, 95% CI 1.04 - 1.28) were associated with development of hearing loss. Amikacin treatment duration modified the effect of the dosage on the risk of hearing loss, increasing this risk as the duration increased. CONCLUSIONS: Amikacin was effective for MDR-TB treatment, but was associated with a high incidence of hearing loss especially in our study population. Total treatment duration and average monthly amikacin dose were associated with improved outcomes; however these were also associated with development of hearing loss.


Subject(s)
Amikacin/adverse effects , Antitubercular Agents/adverse effects , Hearing Loss/chemically induced , Tuberculosis, Multidrug-Resistant/drug therapy , Adolescent , Adult , Amikacin/administration & dosage , Antitubercular Agents/administration & dosage , Drug Administration Schedule , Female , Hearing Loss/epidemiology , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Risk , Treatment Outcome , Young Adult
18.
Front Genet ; 5: 290, 2014.
Article in English | MEDLINE | ID: mdl-25202324

ABSTRACT

A major goal in infectious disease research is to identify the human and pathogenic genetic variants that explain differences in microbial pathogenesis. However, neither pathogenic strain nor human genetic variation in isolation has proven adequate to explain the heterogeneity of disease pathology. We suggest that disrupted co-evolution between a pathogen and its human host can explain variation in disease outcomes, and that genome-by-genome interactions should therefore be incorporated into genetic models of disease caused by infectious agents. Genetic epidemiological studies that fail to take both the pathogen and host into account can lead to false and misleading conclusions about disease etiology. We discuss our model in the context of three pathogens, Helicobacter pylori, Mycobacterium tuberculosis and human papillomavirus, and generalize the conditions under which it may be applicable.

19.
Infect Agent Cancer ; 9: 26, 2014.
Article in English | MEDLINE | ID: mdl-25152769

ABSTRACT

BACKGROUND: The worldwide administration of bivalent and quadrivalent HPV vaccines has resulted in cross-protection against non-vaccine HPV types. Infection with multiple HPV types may offer similar cross-protection in the natural setting. We hypothesized that infections with two or more HPV types from the same species, and independently, infections with two or more HPV types from different species, associate with protection from high-grade lesions. FINDINGS: We recruited a cohort of 94 HIV, HPV-positive women from Botswana, with Grade 2 or higher cervical intraepithelial neoplasia. Infections with 2 or more HPV types from a single species associated with reduced lesion severity in univariate analysis (OR = 0.41, 95% CI 0.18-0.97, p = 0.042), when adjusted for the presence of HPV 16 or 18 types (OR = 0.41, 95% CI 0.17-1.00, p = 0.049), or all high-risk HPV type infections (OR = 0.38, 95% CI 0.16-0.90, p = 0.028). Infections with 2 or more HPV types from different species did not associate (OR = 0.68, 95% CI 0.25-1.81, p = 0.435). CONCLUSIONS: Our findings show that co-infections with genetically similar HPV types reduce the likelihood of progression to high-grade lesions in HIV positive women, an effect not observed in co-infections with taxonomically different HPV types. This observation is possibly caused by an immune cross-protection through a similar mechanism to that observed after HPV vaccination.

20.
BioData Min ; 7: 10, 2014.
Article in English | MEDLINE | ID: mdl-25071867

ABSTRACT

In omic research, such as genome wide association studies, researchers seek to repeat their results in other datasets to reduce false positive findings and thus provide evidence for the existence of true associations. Unfortunately this standard validation approach cannot completely eliminate false positive conclusions, and it can also mask many true associations that might otherwise advance our understanding of pathology. These issues beg the question: How can we increase the amount of knowledge gained from high throughput genetic data? To address this challenge, we present an approach that complements standard statistical validation methods by drawing attention to both potential false negative and false positive conclusions, as well as providing broad information for directing future research. The Diverse Convergent Evidence approach (DiCE) we propose integrates information from multiple sources (omics, informatics, and laboratory experiments) to estimate the strength of the available corroborating evidence supporting a given association. This process is designed to yield an evidence metric that has utility when etiologic heterogeneity, variable risk factor frequencies, and a variety of observational data imperfections might lead to false conclusions. We provide proof of principle examples in which DiCE identified strong evidence for associations that have established biological importance, when standard validation methods alone did not provide support. If used as an adjunct to standard validation methods this approach can leverage multiple distinct data types to improve genetic risk factor discovery/validation, promote effective science communication, and guide future research directions.

SELECTION OF CITATIONS
SEARCH DETAIL
...