Evidence For Genetic Influence Research Articles

The genetic architecture of dog ownership: large-scale genome-wide association study in 97,552 European-ancestry individuals.

Dog ownership has been associated with several complex traits, and there is evidence of genetic influence. We performed a genome-wide association study of dog ownership through a meta-analysis of 31,566 Swedish twins in 5 discovery cohorts and an additional 65,986 European-ancestry individuals in 3 replication cohorts from Sweden, Norway, and the United Kingdom. Association tests with >7.4 million single-nucleotide polymorphisms were meta-analyzed using a fixed effect model after controlling for population structure and relatedness. We identified 2 suggestive loci using discovery cohorts, which did not reach genome-wide significance after meta-analysis with replication cohorts. Single-nucleotide polymorphism-based heritability of dog ownership using linkage disequilibrium score regression was estimated at 0.123 (CI 0.038-0.207) using the discovery cohorts and 0.018 (CI -0.002 to 0.039) when adding in replication cohorts. Negative genetic correlation with complex traits including type 2 diabetes, depression, neuroticism, and asthma was only found using discovery summary data. Furthermore, we did not identify any genes/gene-sets reaching even a suggestive level of significance. This genome-wide association study does not, by itself, provide clear evidence on common genetic variants that influence dog ownership among European-ancestry individuals.

Are Moral Intuitions Heritable?

Two prominent theoretical frameworks in moral psychology, Moral Foundations and Dual Process Theory, share a broad foundational assumption that individual differences in human morality are dispositional and in part due to genetic variation. The only published direct test of heritability, however, found little evidence of genetic influences on moral judgments using instrumentation approaches associated with Moral Foundations Theory. This raised questions about one of the core assumptions underpinning intuitionist theories of moral psychology. Here we examine the heritability of moral psychology using the moral dilemmas approach commonly used in Dual Process Theory research. Using such measures, we find consistent and significant evidence of heritability. These findings have important implications not only for understanding which measures do, or do not, tap into the genetically influenced aspects of moral decision-making, but in better establishing the utility and validity of different intuitionist theoretical frameworks and the source of why people differ in those frameworks.

Heritability of cervical spinal cord structure.

ObjectiveMeasures of spinal cord structure can be a useful phenotype to track disease severity and development; this observational study measures the hereditability of cervical spinal cord anatomy and its correlates in healthy human beings.MethodsTwin data from the Human Connectome Project were analyzed with semiautomated spinal cord segmentation, evaluating test-retest reliability and broad-sense heritability with an AE model. Relationships between spinal cord metrics, general physical measures, regional brain structural measures, and motor function were assessed.ResultsWe found that the spinal cord C2 cross-sectional area (CSA), left-right width (LRW), and anterior-posterior width (APW) are highly heritable (85%–91%). All measures were highly correlated with the brain volume, and CSA only was positively correlated with thalamic volumes (p = 0.005) but negatively correlated with the occipital cortex area (p = 0.001). LRW was correlated with the participant's height (p = 0.00027). The subjects' sex significantly influenced these metrics. Analyses of a test-retest data set confirmed validity of the approach.ConclusionsThis study provides the evidence of genetic influence on spinal cord structure. MRI metrics of cervical spinal cord anatomy are robust and not easily influenced by nonpathological environmental factors, providing a useful metric for monitoring normal development and progression of neurodegenerative disorders affecting the spinal cord, including—but not limited to—spinal cord injury and MS.

Identifying subtypes of cannabis users based on simultaneous polysubstance use

BackgroundCannabis use patterns vary considerably, with many users reporting simultaneous and non-simultaneous use (co-use) of other substances. Despite this, little research has examined the extent to which subtypes of cannabis users may be identified based on their simultaneous and co-use behaviors. MethodsThe sample consisted of adult Australian twins and siblings who reported lifetime cannabis use (n = 2590). A latent class analysis was conducted to determine subtypes of cannabis users based on five indicators of substance co-use and simultaneous use. Adolescent correlates (age of substance initiation and conduct disorder) and adult correlates (substance use/disorder and depression) of class membership were assessed. Twin similarity for class membership was also examined. ResultsFour subtypes of users were identified: 1) alcohol co-users, 2) simultaneous alcohol users, 3) simultaneous tobacco users, and 4) simultaneous alcohol, tobacco, and drug users. Compared to co-users of alcohol, simultaneous alcohol users were at increased risk for alcohol problems. Patterns of use that involved simultaneous tobacco and cannabis use (i.e., simultaneous tobacco users and simultaneous alcohol, tobacco, and drug users) were associated with the most problematic outcomes, including substance use and disorder. There was evidence for genetic influences (12–58%) on cannabis use patterns, with higher concordance for latent class membership among monozygotic compared to dizygotic twins (χ2 (1) = 7.19, p = 0.007). ConclusionsThe current study identified four classes of cannabis users at varying degrees of risk. Results suggest that simultaneous tobacco and cannabis use may be especially associated with deleterious outcomes.

Artificial Selection for Increased Voluntary Wheel Running Alters Limb Skeleton Shape and Exercise Plasticity in Mice

Individual skeletal morphology is determined by genetic effects and within‐generation phenotypic plasticity in response to mechanical loading. Changes in limb bone morphology associated with locomotor activity through ontogeny and across evolutionary time can provide insight into adaptation in locomotor systems. Here, we investigate the effects of long‐term selection for locomotor activity on the gross morphology and exercise response of the hind limb skeleton using a mouse model. A founding population of Hsd:ICR outbred mouse stock was divided into closed lines of “high runner” (HR) and control (C) animals. HR mice were bred for increased voluntary wheel‐running distance by breeding animals (n=10 pairs per generation) with the highest average wheel revolutions on days 5 and 6 of a 6‐day wheel exposure protocol. Control animals were also wheel‐tested but were randomly paired. Male HR and C mice from experimental generation 82 were randomly assigned at 5 weeks of age to be permitted or denied wheel access for 4 weeks, resulting in 4 experimental groups: C wheel (n=12), C no wheel (n=12), HR wheel (n=10), and HR no wheel (n= 10). Following wheel access, mice were euthanized and right hind limbs were micro‐CT scanned (~20 um voxel size). Three‐dimensional shapes of the os coxa, femur, and tibia were defined by digitizing 18, 23, and 18 landmarks, respectively, on each specimen. To adjust for size, individual bones were scaled to the geometric mean of all possible linear distances among landmarks. Between‐group differences were analyzed using canonical variates analysis (CVA) and localized using the Euclidean distance matrix analysis (EDMA) Form procedure. EDMA Growth procedure was used to compare the trajectories of exercise‐induced skeletal plasticity between HR and C animals. Differences ≥3% were considered substantial for both EDMA methods. Shape analyses revealed differences in morphological lability among the three limb bones examined and in subsections within each bone. More specifically, the mean hind limb skeletal morphology, especially of the pelvis and proximal femur, substantially differed between HR and C mice. Plastic bony responses to exercise also differed, most substantially in the iliac blade, ischial tuberosity, and proximal femur. Finally, throughout the hind limb, the baseline skeletal morphology of HR mice did not resemble the exercise response of C animals, indicating that genetic assimilation of plastic bone responses did not occur in this model. The results suggest regional sensitivity of the hind limb skeleton to plastic and evolved morphological change, provide further evidence of genetic influence on bone functional adaptation, and inform our understanding of the evolutionary lability of the musculoskeletal system over evolutionary timescales.Support or Funding InformationUniversity of Missouri School of Medicine, University of Missouri Dissertation Research Travel AwardThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Has the Genetic Contribution to the Propensity to Gamble Increased? Evidence From National Twin Studies Conducted in 1962 and 2002

Social changes, such as the expansion of legal forms of gambling, can influence not only the prevalence of gambling, but can also shape the relative importance of genetic and environmental contributions to individual differences in the propensity to gamble. In the present study, I examined differences in the prevalence and in the relative contribution of genetic and environmental factors to gambling involvement in the United States in 1962 versus 2002. The data came from two sources: (1) a survey of 839 17-year-old same-sex twin pairs from the National Merit Scholarship Qualifying Test twin study, and (2) an interview of 477 18- to 26-year-old same-sex twin pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. Similar measures of gambling participation were included in the two studies. Evidence for a genotype-by-time interaction was evaluated by testing whether the contribution of genetic influences was greater in the more recently born cohort of twins. Despite the major changes in the gambling landscape over the intervening 40 years, there was no evidence for such an interaction. The contribution of genetic factors and environmental factors did not significantly differ and there was no evidence for genetic influences at either time point. Instead, the variation in the propensity to gamble was explained nearly equally by common and unique environmental factors. Explanations for this surprising finding are discussed.

Are Moral Intuitions Heritable?

Two prominent theoretical frameworks in moral psychology, Moral Foundations and Dual Process Theory, share a broad foundational assumption that individual differences in human morality are dispositional and in part due to genetic variation. The only published direct test of heritability, however, found little evidence of genetic influences on moral judgements using instrumentation approaches associated with Moral Foundations Theory. This raised questions about one of the core assumptions underpinning intuitionist theories of moral psychology. Here we examine the heritability of moral psychology using the moral dilemmas approach commonly used in Dual Process Theory research. Using such measures, we find consistent and significant evidence of heritability. These findings have important implications not only for understanding which measures do, or do not, tap into the genetically influenced aspects of moral decision making, but in better establishing the utility and validity of different intuitionist theoretical frameworks and the source of why people differ in those frameworks.

ACE gene variants and sarcoidosis in a Finnish population.

Background: Sarcoidosis is a systemic inflammatory disease with unknown etiology. However, there is a strong evidence of genetic influence in sarcoidosis. Objectives: We wanted to extend our knowledge of the role of the whole ACE gene, not only insertion/deletion (I/D) polymorphism, in a Finnish sarcoidosis population by genotyping the ACE gene region from 5' upstream to the 3' downstream. Methods: We genotyped 29 single nucleotide polymorphisms (SNPs) spanning the ACE gene from 188 sarcoidosis patients (resolved disease, n=90; persistent disease, n=98) and from 150 controls. These SNPs included tag SNP rs4343 for I/D polymorphism. To replicate the study we genotyped 11 of these SNPs from 139 Czech sarcoidosis patients (resolved disease, n=47; persistent disease, n=92) and 176 healthy controls. Results: No association was detected between I/D genotypes and disease susceptibility or prognosis. We found a novel SNP (rs9905945) in the 5'upstream region of the ACE gene to be moderately associated with favourable disease prognosis in Finnish patients [p=0.035, OR=2.034 (95%CI 1.045-3.960)]. However, in the replication study in Czechs, the SNP rs9905945 did not show association with prognosis of sarcoidosis. Conclusions: This study further characterizes genetic distinctions between Finnish sarcoidosis patients with different prognosis and population-specific genotype distribution of ACE variants. Nevertheless it seems that variants in the ACE gene do not considerably influence the course of the disease in Finnish sarcoidosis patients. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 104-114).

Heritability of brain activity related to response inhibition: A longitudinal genetic study in adolescent twins

The ability to inhibit prepotent but context- or goal-inappropriate responses is essential for adaptive self-regulation of behavior. Deficits in response inhibition, a key component of impulsivity, have been implicated as a core dysfunction in a range of neuropsychiatric disorders such as ADHD and addictions. Identification of genetically transmitted variation in the neural underpinnings of response inhibition can help to elucidate etiological pathways to these disorders and establish the links between genes, brain, and behavior. However, little is known about genetic influences on the neural mechanisms of response inhibition during adolescence, a developmental period characterized by weak self-regulation of behavior. Here we investigated heritability of ERPs elicited in a Go/No-Go task in a large sample of adolescent twins assessed longitudinally at ages 12, 14, and 16. Genetic analyses showed significant heritability of inhibition-related frontal N2 and P3 components at all three ages, with 50 to 60% of inter-individual variability being attributable to genetic factors. These genetic influences included both common genetic factors active at different ages and novel genetic influences emerging during development. Finally, individual differences in the rate of developmental changes from age 12 to age 16 were significantly influenced by genetic factors. In conclusion, the present study provides the first evidence for genetic influences on neural correlates of response inhibition during adolescence and suggests that ERPs elicited in the Go/No-Go task can serve as intermediate neurophysiological phenotypes (endophenotypes) for the study of disinhibition and impulse control disorders.

Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins

Detection and evaluation of the mismatch between the intended and actually obtained result of an action (reward prediction error) is an integral component of adaptive self-regulation of behavior. Extensive human and animal research has shown that evaluation of action outcome is supported by a distributed network of brain regions in which the anterior cingulate cortex (ACC) plays a central role, and the integration of distant brain regions into a unified feedback-processing network is enabled by long-range phase synchronization of cortical oscillations in the theta band. Neural correlates of feedback processing are associated with individual differences in normal and abnormal behavior, however, little is known about the role of genetic factors in the cerebral mechanisms of feedback processing. Here we examined genetic influences on functional cortical connectivity related to prediction error in young adult twins (age 18, n=399) using event-related EEG phase coherence analysis in a monetary gambling task. To identify prediction error-specific connectivity pattern, we compared responses to loss and gain feedback. Monetary loss produced a significant increase of theta-band synchronization between the frontal midline region and widespread areas of the scalp, particularly parietal areas, whereas gain resulted in increased synchrony primarily within the posterior regions. Genetic analyses showed significant heritability of frontoparietal theta phase synchronization (24 to 46%), suggesting that individual differences in large-scale network dynamics are under substantial genetic control. We conclude that theta-band synchronization of brain oscillations related to negative feedback reflects genetically transmitted differences in the neural mechanisms of feedback processing. To our knowledge, this is the first evidence for genetic influences on task-related functional brain connectivity assessed using direct real-time measures of neuronal synchronization.

Regional Cortical Surface Area in Adolescents: A Preliminary MRI Twin Study of Genetic and Environmental Contributions.

Cortical surface area (CSA) has particular relevance for understanding development, behavior, and the connection between brain structure and function. Little is known about genetic and environmental determinants of CSA during development. We utilized bivariate twin methods to identify global and regionally specific genetic factors which influence CSA in a preliminary sample of typically-developing adolescents, with hypotheses based on findings in middle-aged adults. Similar to previous findings, we observed high heritability for total CSA. There was also significant evidence for genetic influences on regional CSA, particularly when these were not adjusted for total CSA, with highest heritability in frontal cortex and relatively fewer genetic contributions to medial temporal cortical structures. Adjustment for total CSA reduced regional CSA heritability dramatically, but a moderate influence of genetic factors remained in some regions. Both global and regionally-specific genetic factors influence regional CSA during adolescence.

Evidence of reactive gene-environment correlation in preschoolers' prosocial play with unfamiliar peers.

The development of prosocial behaviors during the preschool years is essential for children's positive interactions with peers in school and other social situations. Although there is some evidence of genetic influences on prosocial behaviors, very little is known about how genes and environment, independently and in concert, affect prosocial behaviors in young children. This study of 126 twin and sibling pairs examined 5-year-old preschool children's positive behaviors (prosocial and easy-going) while playing freely with an unfamiliar, same-age, same-sex peer. Children were randomly paired, allowing us to rule out passive (parent-influenced environment) and active (child-driven peer choices) gene-environment correlations as potential influences on the results. We found evidence of reactive gene-environment correlation, demonstrating that children who are genetically more likely to act prosocially and to be temperamentally outgoing appear to evoke more prosocial and easy-going behaviors from an unfamiliar peer. We also found that both dominant genetic and nonshared environmental factors were significant influences on preschoolers' prosocial play behaviors, but that neither genetic nor shared environmental factors were significant for easy-going play behaviors. These findings shed important light on influences of prosocial behaviors in preschoolers. Via inherited tendencies, preschool children's positive behaviors evoke similar positive behaviors from their play peers. Given that prosocial behaviors are preludes to a large range of important socially appropriate behaviors, prosocial children should be encouraged to interact with their peers to potentially create a more positive atmosphere within social contexts.

Developmentally dynamic genome: Evidence of genetic influences on increases and decreases in conduct problems from early childhood to adolescence.

The development of conduct problems in childhood and adolescence is associated with adverse long-term outcomes, including psychiatric morbidity. Although genes constitute a proven factor of stability in conduct problems, less is known regarding their role in conduct problems’ developmental course (i.e. systematic age changes, for instance linear increases or decreases).Mothers rated conduct problems from age 4 to 16 years in 10,038 twin pairs from the Twins Early Development Study. Individual differences in the baseline level (.78; 95% CI: .68-.88) and the developmental course of conduct problems (.73; 95% CI: .60-.86) were under high and largely independent additive genetic influences. Shared environment made a small contribution to the baseline level but not to the developmental course of conduct problems. These results show that genetic influences not only contribute to behavioural stability but also explain systematic change in conduct problems. Different sets of genes may be associated with the developmental course versus the baseline level of conduct problems. The structure of genetic and environmental influences on the development of conduct problems suggests that repeated preventive interventions at different developmental stages might be necessary to achieve a long-term impact.

Non-Eosinophilic Nasal Polyps In Second-Generation Asian Patients In The U.S. With Chronic Rhinosinusitis; Evidence For Genetic Influence On Eosinophilia

S U N D A Y 580 Real-Time Asthma Outreach Reduces Excessive Short-Acting Beta-Agonist (SABA) Canister-Dispensing: A Randomized Study Dr. Robert S. Zeiger, MD, PhD, FAAAAI, Dr. Michael Schatz, MD, MS, FAAAAI, Qiaowu Li, MS, Dr. James Zazzali, PhD, Wansu Chen, MS; Kaiser Permanente Southern California, San Diego, CA, Kaiser Permanente Southern California, Pasadena, CA, Genentech, Inc., South San Francisco, CA. RATIONALE: Excessive SABA use indicates impaired asthma. We hypothesized that real-time outreach to excessive SABA users reduces SABA canister-dispensing. METHODS: After real-time determination, using information technology, of a 7 SABA canister-dispensing in the prior 12 months, 12-56 year-olds with physician-coded asthma and inhaled corticosteroid dispensing were block-randomized by prior asthma specialist care and step-care level into intervention (N51001) and control groups (N5998). Intervention included real-time letter notification to patient and electronic message to their physician with management suggestions including facilitated allergy referral for patients without prior asthma specialist care. The control group received standard Managed Care Organization (MCO) asthma care without research contact. Frequency and time to 7SABA canister-dispensing in the follow-up year were the primary outcomes. RESULTS: Intervention compared to controls reached 7 SABA canister-dispensings less frequently (50.7% versus 57.1%; risk ratio, 0.89; 95% CI, 0.82-0.97; P50.007) and later (median 246 versus 225 days; Hazard ratio, 0.80; 95% CI, 0.71-0.91; P _0.5 was more frequent in the intervention group (P<0.001). The subgroup without prior specialist care achieved these benefits [P for interaction: frequency of (P50.04) and time (P50.007) to 7SABA canister-dispensing; time to allergist visit (P<0.001)]. Exacerbations were unaffected. CONCLUSIONS: A novel administrative-based outreach program improves impairment in patients without prior asthma specialist care and could be adaptable to MCOs with electronic medical records.

Evidence of genetic influence on the flowering pattern of Ficus microcarpa

Flowering patterns result from the interactions between genetic and environmental factors. While the genetic basis for flowering time variation in commercial plants is often well understood, few studies have been conducted to investigate these patterns in plants without economic importance. Ficus microcarpa is a commonly introduced horticultural fig tree. Asynchrony in syconium development and the initiation, frequency, and size of crops may affect its fitness as well as the success of mutualism with its pollinating wasps. In order to identify genetically determined patterns in the flowering traits in F. microcarpa, a 14-month census was taken on the flowering characteristics of 28 trees growing in close proximity along an urban street in Taipei, Taiwan. Weekly surveys were taken on 7 characteristics: crop number, syconia per branch, crop asynchrony, as well as flowering onset and seed development duration for both the spring and summer crops. Post-census genotyping at microsatellite loci distinguished 16 genetic groups (5 clonal groups and 11 non-clone trees). All crop characteristics presented higher variation across different genotype groups than within groups except for seed development duration. We found no evidence of adjacency effects or spatial auto-correlation of flowering traits. The study offers the first evidence of genetic variations in the flowering patterns in a species of Ficus. These findings lend insight into the adaptive characteristics that potentially facilitate the local establishment of F. microcarpa in new locations.

A multivariate twin study of early literacy in Japanese kana

This first Japanese twin study of early literacy development investigated the extent to which genetic and environmental factors influence individual differences in prereading skills in 238 pairs of twins at 42months of age. Twin pairs were individually tested on measures of phonological awareness, kana letter name/sound knowledge, receptive vocabulary, visual perception, nonword repetition, and digit span. Results obtained from univariate behavioral-genetic analyses yielded little evidence for genetic influences, but substantial shared-environmental influences, for all measures. Phenotypic confirmatory factor analysis suggested three correlated factors: phonological awareness, letter name/sound knowledge, and general prereading skills. Multivariate behavioral genetic analyses confirmed relatively small genetic and substantial shared environmental influences on the factors. The correlations among the three factors were mostly attributable to shared environment. Thus, shared environmental influences play an important role in the early reading development of Japanese children.

Born together--reared apart: the landmark Minnesota twin study

The identical Jim were raised in separate families and met for the first time at age thirty-nine, only to discover that they both suffered tension headaches, bit their fingernails, smoked Salems, enjoyed woodworking, and vacationed on the same Florida beach. This example of the potential power of genetics captured widespread media attention in 1979 and inspired the Minnesota Study of Twins Reared Apart. This landmark investigation into the nature-nurture debate shook the scientific community by demonstrating, across a number of traits, that twins reared separately are as alike as those raised together. As a postdoctoral fellow and then as assistant director of the Minnesota Study, Nancy L. Segal provides an eagerly anticipated overview of its scientific contributions and their effect on public consciousness. The study's evidence of genetic influence on individual differences in traits such as personality (50 per cent) and intelligence (70 per cent) overturned conventional ideas about parenting and teaching. Treating children differently and nurturing their inherent talents suddenly seemed to be a fairer approach than treating them all the same. Findings of genetic influence on physiological characteristics such as cardiac and immunologic function have led to more targeted approaches to disease prevention and treatment. And indications of a stronger genetic influence on male than female homosexuality have furthered debate regarding sexual orientation.

Heritability in Cognitive Performance: Evidence Using Computer-Based Testing

ABSTRACT There is overwhelming evidence of genetic influence on cognition. The effect is seen in general cognitive ability, as well as in specific cognitive domains. A conventional assessment approach using face-to-face paper and pencil testing is difficult for large-scale studies. Computerized neurocognitive testing is a suitable alternative. A total of 267 parent–child dyads were selected from a larger database of computerized neurocognitive test results. Correlations were determined between parent–child dyads, as well as matched parent–child dyads. Univariate regression analyses were estimated to determine the extent to which children's performance could be accounted for by that of their parents, compared with matched control parents. Multiple significant positive correlations in neurocognitive test performance were found in parent–child dyads. Parent performance accounted for a greater proportion of variability in every case. These findings indicated that a computerized neurocognitive battery is an effective tool for studying heritability in cognitive performance in a large sample.

Association of genetic variation with systolic and diastolic blood pressure among African Americans: the Candidate Gene Association Resource study.

The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexity.

Evaluating a Cognitive Model of ALDH2 and Drinking Behavior

Despite evidence for genetic influences on alcohol use and alcohol-related cognitions, genetic factors and endophenotypes are rarely incorporated in cognitive models of drinking behavior. This study evaluated a model of ALDH2 and drinking behavior stipulating cognitive factors and alcohol sensitivity as accounting for genetic influences on drinking outcomes. Participants were Asian-American young adults (n = 171) who completed measures of alcohol cognitions (drinking motives, drinking refusal self-efficacy, and alcohol expectancies), alcohol sensitivity, drinking behavior, and alcohol-related problems as part of a prospective study. Structural equation modeling (SEM) evaluated a model of drinking behavior that stipulated indirect effects of ALDH2 on drinking outcomes through cognitive variables and alcohol sensitivity. The full model provided an adequate fit to the observed data, with the measurement model explaining 63% of the variance in baseline heavy drinking and 50% of the variance in alcohol-related problems at follow-up. Associations of ALDH2 with cognitive factors and alcohol sensitivity were significant, whereas the association of ALDH2 with drinking was not significant with these factors included in the model. Mediation tests indicated significant indirect effects of ALDH2 through drinking motives, drinking refusal self-efficacy, and alcohol sensitivity. Results are consistent with the perspective that genetic influences on drinking behavior can be partly explained by learning mechanisms and implicate cognitive factors as important for characterizing associations of ALDH2 with drinking.