Screening for mitochondrial tRNA variants in 200 patients with systemic lupus erythematosus
Systemic lupus erythematosus (SLE) is a common autoimmune disease with unknown etiology. Recently, a growing number of evidence suggested that mitochondrial dysfunctions played active roles in the pathogenesis of SLE, but its detailed mechanism remains largely undetermined. The aim of this study was to analysis the frequencies of mitochondrial tRNA (mt-tRNA) variants in Chinese individuals with SLE.
Implications of the Co-Dominance Model for Hardy-Weinberg Testing in Genetic Association Studies
The standard way of using tests for compatibility of genetic markers with the Hardy-Weinberg equilibrium (HWE) assumptionvas a means of quality control in genetic association studies (GAS) is to vcarry out this step of preliminary data analysis with the sample of non-diseased vindividuals only. We show that this strategy has no rational basis whenever the genotype--phenotype relation for avmarker under consideration satisfies the assumption of co-dominance.
Place of concordance-discordance model in evaluating NGS performance
Ideally, evaluating NGS performance requires a gold standard; in its absence, concordance between replicates is often used as substitute standard. However, the appropriateness of the concordance-discordance criterion has been rarely evaluated. This study analyzes the relationship between the probability of discordance and the probability of error under different conditions.
The prevalence of JAK2 exon12 mutations in Vietnamese patients with JAK2 V617F-negative polycythemia vera: frequent or rare?
Purpose Polycythemia vera is a hematological malignancy characterized by the overproduction of red blood cells in the bone marrow. Pathogenesis of Polycythemia vera was thought to be caused by genetic mutations of the Janus kinase 2 (JAK2) gene, especially the JAK2 V617F and exon 12 mutations since those mutations were found frequently in the patients. The prevalence of JAK2 exon 12 mutations among Polycythemia Vera patients in Vietnam has not been studied yet. Objectives The overall study objective is to investigate the frequency of JAK2 exon 12 mutations among V617F-negative Polycythemia Vera patients in Vietnam. Methods In this study, the occurrence of these mutations was investigated in a clinical population of 76 Vietnamese Polycythemia Vera patients by PCR-RFLP and Sanger sequencing. Results The result showed that 53 of the patients were V617F-positive, and in 23 V617F-negative patients, only four individuals carried two JAK2 exon 12 mutations. Analysis by different in-silico tools predicted that all the two exon 12 mutations detected in this study (JAK2 c.1592A>G; p.H531R and c.1616A>G p.K539R) were benign. Conclusion These results suggested that the causative mutations in this V617F-negative subgroup might locate in another genetic region, and mutations in exon 12 might not be as common among the V617F-negative Polycythemia Vera patients as thought.
Mutational Screening for Mitochondrial tRNA Genes in 100 Women with Pre-eclampsia
Impairment of mitochondrial function caused by pathogenic mitochondrial DNA (mtDNA) mutations has been found to be associated with pre-eclampsia (PE). However, the underlying mechanism of PE remains poorly undetermined. The aim of this study is to evaluate the relationship between mitochondrial tRNAs (mt-tRNAs) variants and PE.
Violation of the Constant Genetic Effect Assumption Can Result in Biased Estimates for Non-Linear Mendelian Randomization
Non-linear Mendelian randomization is an extension of conventional Mendelian randomization that performs separate instrumental variable analyses in strata of the study population with different average levels of the exposure. The approach estimates a localized average causal effect function, representing the average causal effect of the exposure on the outcome at different levels of the exposure. The commonly used residual method for dividing the population into strata works under the assumption that the effect of the genetic instrument on the exposure is linear and constant in the study population. However, this assumption may not hold in practice.
Reduction of Missed Diagnosis of G6PD Deficiency in Heterozygous Females by G6PD/6PGD Ratio Assay Combined with Amplification Refractory Mutation System PCR
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder that results in impaired enzyme activity. The G6PD/6PGD ratio assay was routinely used for G6PD deficiency screening in China, but there is an apparent defect of missed diagnosis in heterozygous females. The study aims to explore the means to improve its accuracy.
Two Novel Variants of the CAPN3 Gene in Chinese Patients with Limb-Girdle Muscular Dystrophy Recessive 1
Recessive mutations in the CAPN3 gene can lead to limb-girdle muscular dystrophy recessive 1 (LGMD R1). Targeted next-generation sequencing facilitates the discovery of new mutations linked with disease, owing to its ability to selectively enrich specific genomic regions.
Identification of a Hypoxia-Related Signature as Candidate Detector for Schizophrenia Based on Genome-Wide Gene Expression
Schizophrenia (SCZ), a severe neuropsychiatric disorder with high genetic susceptibility, has high rates of misdiagnosis due to the unavoidably subjective factors and heterogeneous clinical presentations. Hypoxia has been identified as an importantly risk factor that participates in the development of SCZ. Therefore, development of a hypoxia-related biomarker for SCZ diagnosis is promising. Therefore, we dedicated to develop a biomarker that could contribute to distinguishing healthy controls and SCZ patients.
A Comprehensive Study of Disease-Causing Variants in PAH, QDPR, PTS, and PCD Genes in Iranian Patients with Hyperphenylalaninemia: A Systematic Review
Hyperphenylalaninemia (HPA) is an autosomal recessive disorder that results from a deficiency in the phenylalanine hydroxylase enzyme (PAH) or from a flaw in the genes that are responsible for the biosynthesis or regeneration of the cofactor tetrahydrobiopterin (BH4), including GCH1, SR, QDPR, PTS, and PCD. Identification of disease-causing variants in these genes can help physicians and clinical geneticists in differential diagnosis, appropriate prescription drugs, and saving time and cost. This study attempted to identify these genes' most prevalent disease-causing variants in Iranian HPA patients.
A Common Variant of ARRB2 Promoter Region Associated with the Prognosis of Heart Failure
The role of ARRB2 in cardiovascular disease has recently gained increasing attention. However, the association between ARRB2 polymorphisms and heart failure (HF) has not yet been investigated.
Polymorphisms of Placental Iodothyronine Deiodinase Genes in a Rural Area of Northern China with High Prevalence of Neural Tube Defects
We have reported that high total homocysteine and the coexistence of inadequate thyroid hormones in maternal serum increase the risk of fetal neural tube defects (NTDs). Placental iodothyronine deiodinases (DIOs: DIO1, DIO2, and DIO3) play a role in regulating the conversions between different forms of maternal thyroid hormones. This study hypothesized that single nucleotide polymorphisms (SNPs) in placental DIOs genes could be related to NTDs.
The Diagnostic Value of miR-124a Expression in Peripheral Blood and Synovial Fluid of Patients with Rheumatoid Arthritis
Rheumatoid arthritis (RA), a chronic autoimmune disorder, is currently a severe health threat. Previous studies have documented the altered expression of various miRNAs in RA patients. This study determined the expression of miR-124a in RA patients and estimated its diagnostic value for RA.
Methods and Software to Analyze Gene-Environment Interactions under a Case-Mother-Control-Mother Design with Partially Missing Child Genotype
The case-mother-control-mother design allows to study fetal and maternal genetic factors together with environmental exposures on early life outcomes. Mendelian constraints and conditional independence between child genotype and environmental factors enabled semiparametric likelihood methods to estimate logistic models with greater efficiency than standard logistic regression. Difficulties in child genotype collection require methods handling missing child genotype.
A Statistical Testing Strategy Accounting for Random and Nonrandom (Skewed) X-Chromosome Inactivation Identifies Lung Cancer Susceptibility Loci among Smokers
Lung cancer is the most common cancer worldwide in mortality and the second in incidence. Epidemiological studies found a higher lung cancer risk for smoking women in comparison to men, but these sex differences, irrespective of smoking habits, remain controversial. One of the hypotheses concerns the genetic contribution of the sex chromosomes. However, while genome-wide association studies identified many lung cancer susceptibility loci, these analyses have excluded X-linked loci.
A Novel PMVK Variant Associated with Familial Porokeratosis
Porokeratosis is a rare chronic progressive hypokeratotic skin disease, possibly related to the mevalonate pathway. Variations in four enzymes, including phosphomevalonate kinase (PMVK) may alter this pathway, ultimately leading to porokeratosis.
A Novel c.3636-4 A>G Mutation in the CCDC88C Plays a Causative Role in Familial Spinocerebellar Ataxia
Spinocerebellar ataxia (SCA) is an autosomal dominant genetic disease characterized by cerebellar neurological deficits. Specifically, its primary clinical manifestation is ataxia accompanied by peripheral nerve damage. A total of 48 causative genes of SCA have been identified. This study aimed to identify causative genes of autosomal dominant SCA in a four-generation Chinese kindred comprising eight affected individuals.
Joint Linkage and Association Analysis Using GENEHUNTER-MODSCORE with an Application to Familial Pancreatic Cancer
Joint linkage and association (JLA) analysis combines two disease gene mapping strategies: linkage information contained in families and association information contained in populations. Such a JLA analysis can increase mapping power, especially when the evidence for both linkage and association is low to moderate. Similarly, an association analysis based on haplotypes instead of single markers can increase mapping power when the association pattern is complex.
Investigation of Recessive Effects of Coding Variants on Common Clinical Phenotypes in Exome-Sequenced UK Biobank Participants
Previous studies have demonstrated effects of rare coding variants on common, clinically relevant phenotypes although the additive burden of these variants makes only a small contribution to overall trait variance. Although recessive effects of individual homozygous variants have been studied, little work has been done to elucidate the impact of rare coding variants occurring together as compound heterozygotes.
comorbidPGS: An R Package Assessing Shared Predisposition between Phenotypes Using Polygenic Scores
Polygenic score (PGS) is a valuable method for assessing the estimated genetic liability to a given outcome or genetic variability contributing to a quantitative trait. While polygenic risk scores are widely used for complex traits, their application in uncovering shared genetic predisposition between phenotypes, i.e., when genetic variants influence more than one phenotype, remains limited.