The Influence of Tissue Plasminogen Activator I/D Polymorphism on the tPA Response to Exercise.

The purpose was to determine if the Alu-insertion (I)/deletion (D) polymorphism of the tissue plasminogen activator (tPA) gene influences the tPA response to maximal exercise. Fifty male subjects (age = 23.6 ± 4.

Annexin A5 is the Most Abundant Membrane-Associated Protein in Stereocilia but is Dispensable for Hair-Bundle Development and Function.

The phospholipid- and Ca(2+)-binding protein annexin A5 (ANXA5) is the most abundant membrane-associated protein of ~P23 mouse vestibular hair bundles, the inner ear's sensory organelle. Using quantitative mass spectrometry, we estimated that ANXA5 accounts for ~15,000 copies per stereocilium, or ~2% of the total protein there. Although seven other annexin genes are expressed in mouse utricles, mass spectrometry showed that none were present at levels near ANXA5 in bundles and none were upregulated in stereocilia of Anxa5(-/-) mice.

Neuropsychological performance measures as intermediate phenotypes for attention-deficit/hyperactivity disorder: A multiple mediation analysis.

Genetic influences on dopaminergic neurotransmission have been implicated in attention-deficit hyperactivity disorder (ADHD) and are theorized to impact cognitive functioning via alterations in frontal-striatal circuitry. Neuropsychological functioning has been proposed to account for the potential associations between dopamine candidate genes and ADHD. However, to date, this mediation hypothesis has not been directly tested.

Variation in an Iron Metabolism Gene Moderates the Association Between Blood Lead Levels and Attention-Deficit/Hyperactivity Disorder in Children.

Although attention-deficit/hyperactivity disorder (ADHD) is a heritable neurodevelopmental condition, there is also considerable scientific and public interest in environmental modulators of its etiology. Exposure to neurotoxins is one potential source of perturbation of neural, and hence psychological, development. Exposure to lead in particular has been widely investigated and is correlated with neurodevelopmental outcomes, including ADHD.

Does 5HTTLPR Genotype Moderate the Association of Family Environment With Child Attention-Deficit Hyperactivity Disorder Symptomatology?

Problematic family dynamics are common among youth with attention-deficit hyperactivity disorder (ADHD). Multiple mechanisms, including diathesis-stress (vulnerability) and differential susceptibility Gene × Environment interaction effects (G × E), have been proposed to account for this association. G × E effects for ADHD were examined via interactions between a genetic marker hypothesized to influence sensitivity to the environment (the promoter polymorphism of the serotonin transporter gene -5HTTLPR) and family conflict and cohesion in predicting ADHD symptoms.

Challenges and solutions for gene identification in the presence of familial locus heterogeneity.

Next-generation sequencing (NGS) of exomes and genomes has accelerated the identification of genes involved in Mendelian phenotypes. However, many NGS studies fall short of identifying causal variants, with estimates for success rates as low as 25% for uncovering the pathological variant underlying disease etiology. An important reason for such failures is familial locus heterogeneity, where within a single pedigree causal variants in two or more genes underlie Mendelian trait etiology.

Pedigree structure and kinship measurements of a mid-Michigan community: a new North American population isolate identified.

Previous studies identified a cluster of individuals with an autosomal recessive form of deafness that reside in a small region of mid-Michigan. We hypothesized that affected members from this community descend from a defined founder population. Using public records and personal interviews, we constructed a genealogical database that includes the affected individuals and their extended families as descendants of 461 settlers who emigrated from the Eifel region of Germany between 1836 and 1875.

Distribution and Severity of Neuropathology in β-Mannosidase-Deficient Mice is Strain Dependent.

Neurological dysfunction is common in humans and animals with lysosomal storage diseases. β-Mannosidosis, an autosomal recessive inherited disorder of glycoprotein catabolism caused by deficiency of the lysosomal enzyme β-mannosidase, is characterized by intracellular accumulation of small oligosaccharides in selected cell types. In ruminants, clinical manifestation is severe, and neuropathology includes extensive intracellular vacuolation and dysmyelination.

A novel actin mRNA splice variant regulates ACTG1 expression.

Cytoplasmic actins are abundant, ubiquitous proteins in nucleated cells. However, actin expression is regulated in a tissue- and development-specific manner. We identified a novel cytoplasmic-γ-actin (Actg1) transcript that includes a previously unidentified exon (3a).

Angiotensinogen promoter polymorphisms predict low diffusing capacity in U.S. and Spanish IPF cohorts.

Background: Single nucleotide polymorphisms (SNPs) in angiotensinogen (AGT) at positions -20 and -6 are associated with increased severity and progression of various fibrotic diseases. Our earlier work demonstrated that the progression of idiopathic pulmonary fibrosis (IPF) was associated with the A-6 allele. This study examined the hypothesis that the homozygous CC genotype at -20 and the AA genotype at -6 would confer worse measures of pulmonary function (measured by pulmonary function tests) in IPF.

Diversity in pathways to common childhood disruptive behavior disorders.

Oppositional-Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are highly comorbid, a phenomenon thought to be due to shared etiological factors and mechanisms. Little work has attempted to chart multiple-level-of-analysis pathways (i.e.

Actin in hair cells and hearing loss.

Hereditary deafness is genetically heterogeneous such that mutations of many different genes can cause hearing loss. This review focuses on the evidence and implications that several of these deafness genes encode actin-interacting proteins or actin itself. There is a growing appreciation of the contribution of the actin interactome in stereocilia development, maintenance, mechanotransduction and malfunction of the auditory system.

Life stressors and 5-HTTLPR interaction in relation to midpregnancy depressive symptoms among African-American women.

Objective: In earlier analyses of nonHispanic White women we found a stronger relation between abuse history and midpregnancy elevated depressive symptoms in women with the serotonin transporter (5-HTTLPR) S/S genotype. Here, we focus on African-American women (N=698). Our inquiry is motivated by racial differences in depression diagnosis/treatment, stressors, and frequency of major 5-HTTLPR alleles (S, LA, LG).

Identification of ATPAF1 as a novel candidate gene for asthma in children.

Background: Asthma is a common disease of children with a complex genetic origin. Understanding the genetic basis of asthma susceptibility will allow disease prediction and risk stratification.

Objective: We sought to identify asthma susceptibility genes in children.

Innate immune system gene polymorphisms in maternal and child genotype and risk of preterm delivery.

Objective: There is little information about the combination of genetic variability in pregnant women and their children in relation to the risk of preterm delivery (PTD). In a sub-cohort of 487 non-Hispanic white and 288 African-American mother/child pairs, the Pregnancy Outcomes and Community Health Study assessed 10 functional polymorphisms in 9 genes involved in innate immune function.

Methods: Race-stratified weighted logistic regression models were used to calculate odds ratios for genotype and PTD/PTD subtypes.

Interplay of cytokine polymorphisms and bacterial vaginosis in the etiology of preterm delivery.

Recent findings suggest that the association between inflammation-related genes and preterm delivery may be stronger in the presence of bacterial vaginosis (BV). Tumor necrosis factor-alpha (TNFα) and interleukin 1-beta (IL-1β) are pro-inflammatory cytokines capable of inducing preterm labor in non-human primates. In this study the authors tested associations among two TNFα promoter polymorphisms (-G308A and -G238A), a single IL-1β polymorphism (+C3954T), vaginal microbial findings, and risk of preterm delivery.

The dopamine receptor D4 gene (DRD4) moderates family environmental effects on ADHD.

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prime candidate for exploration of gene-by-environment interaction (i.e., G x E), particularly in relation to dopamine system genes, due to strong evidence that dopamine systems are dysregulated in the disorder.

Gene x environment interactions for ADHD: synergistic effect of 5HTTLPR genotype and youth appraisals of inter-parental conflict.

Background: Serotonin genes have been hypothesized to play a role in the etiology of attention-deficit hyperactivity disorder (ADHD); prior work suggests that serotonin may interact with psychosocial stressors in ADHD, perhaps via mechanisms involved in emotional dysregulation. Because the development of behavioral and emotional regulation depends heavily both on the child's experience within the family context and the child's construals of that experience, children's appraisals of inter-parental conflict are a compelling candidate potentiator of the effects of variation within the serotonin transporter gene promoter polymorphism (5HTTLPR) on liability for ADHD.

Method: 304 youth from the local community underwent a multi-informant diagnostic assessment procedure to identify ADHD cases and non-ADHD controls.

Ion-dependent polymerization differences between mammalian beta- and gamma-nonmuscle actin isoforms.

beta- and gamma-nonmuscle actins differ by 4 amino acids at or near the N terminus and distant from polymerization interfaces. beta-Actin contains an Asp(1)-Asp(2)-Asp(3) and Val(10) whereas gamma-actin has a Glu(1)-Glu(2)-Glu(3) and Ile(10). Despite these small changes, conserved across mammals, fish, and birds, their differential localization in the same cell suggests they may play different roles reflecting differences in their biochemical properties.

Personality mediation of genetic effects on Attention-Deficit/Hyperactivity Disorder.

Personality traits may be viable candidates for mediators of the relationship between genetic risk and ADHD. Participants were 578 children (331 boys; 320 children with ADHD) between the ages of six and 18. Parents and teachers completed a comprehensive, multi-stage diagnostic procedure to assess ADHD and comorbid disorders.

Confirmation and extension of association of blood lead with attention-deficit/hyperactivity disorder (ADHD) and ADHD symptom domains at population-typical exposure levels.

Background: Recent studies have suggested that child attention-deficit/hyperactivity disorder (ADHD) and its symptom domains are related to blood lead level, even at background exposure levels typical in western countries. However, recent studies disagreed as to whether lead was related to inattention or hyperactivity-impulsivity within the ADHD domain. More definitive evaluation of these questions was sought.

Polymorphisms in thrombophilia and renin-angiotensin system pathways, preterm delivery, and evidence of placental hemorrhage.

Objective: The purpose of this study was to analyze functional polymorphisms in candidate genes (methylenetetrahydrofolate reductase [MTHFR]677C>T, MTHFR1298A>C, factor 5 1691G>A [FVL], and angiotensinogen (AGT)-6G>A) in relation to a hypothesized placental hemorrhage pathway to preterm delivery (PTD).

Study Design: We assessed maternal genotypes, pregnancy outcomes, and placental pathologic evidence among 560 white and 399 black women who were recruited at mid trimester into a prospective cohort study (1998-2004). Odds of dominant genotypes were calculated for PTDs with (n = 56) or without (n = 177) evidence of placental hemorrhage (referent = term) with the use of race-stratified polytomous logistic regression models.

Gamma-actin is required for cytoskeletal maintenance but not development.

Beta(cyto)-actin and gamma(cyto)-actin are ubiquitous proteins thought to be essential building blocks of the cytoskeleton in all non-muscle cells. Despite this widely held supposition, we show that gamma(cyto)-actin null mice (Actg1(-/-)) are viable. However, they suffer increased mortality and show progressive hearing loss during adulthood despite compensatory up-regulation of beta(cyto)-actin.

SNP discovery and haplotype analysis in the segmentally duplicated DRD5 coding region.

The dopamine receptor 5 gene (DRD5) holds much promise as a candidate locus for contributing to neuropsychiatric disorders and other diseases influenced by the dopaminergic system, as well as having potential to affect normal behavioral variation. However, detailed analyses of this gene have been complicated by its location within a segmentally duplicated chromosomal region. Microsatellites and SNPs upstream from the coding region have been used for association studies, but we find, using bioinformatics resources, that these markers all lie within a previously unrecognized second segmental duplication (SD).