Differential Susceptibility: The Genetic Moderation of Peer Pressure on Alcohol Use

FBXO11 variants are associated with intellectual disability and variable clinical manifestation in Chinese affected individuals

F-box protein 11 (FBXO11) is a member of F-Box protein family, which has recently been proved to be associated with intellectual developmental disorder with dysmorphic facies and behavioral abnormalities (IDDFBA, OMIM: 618089). In this study, 12 intellectual disability individuals from 5 Chinese ID families were collected, and whole exome sequencing (WES), sanger sequencing, and RNA sequencing (RNA-seq) were conducted. Almost all the affected individuals presented with mild to severe intellectual disability (12/12), global developmental delay (10/12), speech and language development delay (8/12) associated with a range of alternate features including increased body weight (7/12), short stature (6/12), seizures (3/12), reduced visual acuity (4/12), hypotonia (1/12), and auditory hallucinations and hallucinations (1/12). Distinguishingly, malformation was not observed in all the affected individuals. WES analysis showed 5 novel FBXO11 variants, which include an inframe deletion variant, a missense variant, two frameshift variants, and a partial deletion of FBXO11 (exon 22-23). RNA-seq indicated that exon 22-23 deletion of FBXO11 results in a new mRNA structure. Conservation and protein structure prediction demonstrated deleterious effect of these variants. The DEGs analysis revealed 148 differentially expressed genes shared among 6 affected individuals, which were mainly associated with genes of muscle and immune system. Our research is the first report of FBXO11-associated IDDFBA in Chinese individuals, which expands the genetic and clinical spectrum of this newly identified NDD/ID syndrome.

Contextual effects of community capacity as a predictor for adolescent alcohol, tobacco, and illicit drug use: A multi-level analysis

Adolescent substance use is a major public health issue that can result in enduring physical, psychological, and social consequences. This study seeks to examine the relationship between community capacity for prevention and the 4-week prevalence rate of substance use, including tobacco, alcohol, other drugs, and binge-drinking, among students in Germany ranging from grades 5 to 11. This study employed a cross-sectional design and used baseline data from 28 communities participating in the CTC-EFF study. The sample consisted of 7210 students who were surveyed about their substance use behavior. Additionally, 158 local key informants were surveyed on ten capacity domains, which included commitment, knowledge and skills, resources, leadership, inclusiveness, prevention collaboration, sectoral-collaboration, cohesion, problem-solving skills, and needs orientation. Furthermore, a total capacity score was calculated as the mean of the ten capacity domains. To examine the associations between community capacity and substance use behavior, logistic multi-level models were utilized. The analysis shows a negative association between community capacity (total score) and any substance use (OR = 0.28, 95% CI 0.12-0.56). Specifically, higher levels of total community capacity are associated with lower odds of alcohol use (OR = 0.30, 95% CI 0.13-0.80), tobacco use (OR = 0.09, 95% CI 0.01-0.60), and binge-drinking (OR = 0.67, 95% CI (0.46-0.99). Further analyses of distinct community capacity domains indicate that higher levels of sectoral-collaboration (OR = 0.62, 95% CI 0.37-0.97), knowledge and skills (OR = 0.74, 95% CI 0.40-0.79), resources (OR = 0.52, 95% CI 0.36-0.76), and problem-solving skills (OR = 0.71, 95% CI 0.36-0.89) are associated with lower odds of any substance use. The study findings suggest that community capacity is associated with substance use behavior, emphasizing the importance of capacity building in interventions targeting the reduction of substance use among adolescents.

Whole exome sequencing and transcriptome analysis in two unrelated patients with novel SET mutations

The human SET nuclear proto-oncogene (SET) gene is a protein-coding gene that encodes proteins that affects chromatin remodeling and gene transcription. Mutations in the SET gene have been reported to cause intellectual disability (ID) and epilepsy. In this study, we collected and analyzed clinical, genetic, and transcript features of two unrelated Chinese patients with ID. Both patients were characterized by moderate intellectual disability. Whole-exome sequencing identified two novel heterozygous mutations in the SET gene: NM_001122821.1:c.532-3 T > A and NM_001122821.1:c.3 G > C (p.0?). Additionally, RNA sequencing revealed widespread dysregulation of genes involved in NF-kB signaling and neuronal system in these two patients. To our knowledge, this is the first report of SET mutations causing ID in the Chinese population, broadening the genetic and ethnic spectrum of SET-related disorders and highlighting the importance of screening for SET gene variants.

Expanding the mutational and clinical spectrum of Chinese intellectual disability patients with two novel CTCF variants

CCCTC-Binding Factor (CTCF) is a protein-coding gene involved in transcriptional regulation, insulator activity, and regulation of chromatin structure, and is closely associated with intellectual developmental disorders. In this study, we report two unrelated Chinese patients with intellectual disability (ID). According to variant interpretation results from exome sequencing data and RNA-seq data, we present two novel heterozygous CTCF variants, NM_006565.3:c.1519_2184del (p. Glu507_Arg727delins47) and NM_006565.3:c.1838_1852del (p.Glu613_Pro617del), found in two distinct unrelated patients, respectively. Moreover, RNA-seq data of patient 1 indicated the absence of the mutant transcript, while in patient 2, the RNA-seq data revealed a CTCF mRNA transcript with a deletion of 15 nucleotides. Notably, the RNA sequencing data revealed 507 differentially expressed genes shared between these two patients. Specifically, among them, 194 were down-regulated, and 313 were up-regulated, primarily involved in gene regulation and cellular response. Our study expands the genetic and clinical spectrum of CTCF and advances our understanding of the pathogenesis of CTCF in vivo.

Who Is Exposed to Harmful Online Content? The Role of Risk and Protective Factors Among Czech, Finnish, and Spanish Adolescents

Although adolescents' exposure to harmful online content has been linked to decreased subjective well-being and offline risky behaviors, there is limited research on the factors that underlie such problematic online behavior. Using the conceptual framework of Problem Behavior Theory, this study examined the role of risk (i.e., emotional problems, sensation seeking) and protective (i.e., the quality of family environment, social support from friends) factors in exposure to harmful online content among 4473 12- to 16-year-olds (M = 13.9, SD = 1.3, 49% girls) in the Czech Republic, Finland, and Spain. Individual country samples included 1848 adolescents from the Czech Republic (age: M = 14, SD = 1.4; 51% girls), 788 from Finland (age: M = 13.9, SD = 1.3; 52% girls), and 1837 from Spain (age: M = 13.5, SD = 1.2; 47% girls). In all of the sampled countries, emotional problems and sensation seeking served as risk factors, whereas good family relationships were protective. In some countries, the effects of emotional problems and sensation seeking were moderated by the quality of the family environment and social support from friends. These moderating effects suggest that individual risk factors for exposure to harmful online content may be buffered by a positive family environment and friends' support. The findings revealed similarities in the risk and protective factors underlying online problem behavior across three different countries. They demonstrate that the mechanisms proposed by Problem Behavior Theory can help to understand the etiology of adolescent problem behavior across different countries as well as offline and online contexts.

Longitudinal Links between Adolescent and Peer Conduct Problems and Moderation by a Sensitivity Genetic Index

The most extensively studied influence on adolescent conduct problem behaviors is peers, and the literature points to genetics as one source of individual differences in peer influence. The purpose of this study was to test the hypothesis that an environmental sensitivity genetic index comprised of DRD4, 5-HTTLPR, and GABRA2 variation would moderate the association between peer and adolescent conduct problems. Latent growth modeling was applied to PROSPER project longitudinal data from adolescents and their peers. Results showed the hypothesis was supported; adolescents with more copies of putative sensitivity alleles were more strongly influenced by their peers. The interaction form was consistent with differential susceptibility in follow-up analyses. Strengths and weaknesses of genetic aggregates for sensitivity research are discussed.

Parsing out the role of dopamine D4 receptor gene (DRD4) on alcohol-related phenotypes: A meta-analysis and systematic review

Genetics account for moderate variation of individual differences in developing alcohol use disorder (AUD), but it is unclear which genetic variations contribute to AUD risk. One candidate gene investigated due to its association with AUD is the dopamine D4 receptor gene (DRD4), which contains a 48-base pair variable number tandem repeat (VNTR) in exon 3 of its coding region. To date, no quantitative synthesis of the published literature on the effects of DRD4 VNTR variation on alcohol-related phenotypes has been conducted. MEDLINE, Embase, Web of Science, and PsycInfo were searched for studies that reported on alcohol craving, alcohol consumption, severity of AUD, and case-control (AUD versus no diagnosis of AUD) studies in DRD4L (seven repeats or more) carriers compared with DRD4S (six repeats or less) homozygotes. Random-effects meta-analysis was used for all analyses. A pooled sample size of 655 to 13,360 of 28 studies were included. Compared with DRD4S homozygotes, DRD4L carriers had increased number of drinking days (SMD: 0.205; 95% CI: 0.008 to 0.402), binge drinking days (SMD: 0.217; 95% CI: 0.0532 to 0.380), and severity of AUD (SMD: 0.143; 95% CI: 0.028 to 0.259). There was no difference between DRD4 VNTR genotypes on drinks per drinking day, largest number of drinks per day/occasion, and case-control analysis. It was not possible to conduct a meta-analysis of the craving data, but a systematic review of this literature found mixed results on DRD4 VNTR genotype effect. The present meta-analysis suggests DRD4 VNTR variation may be a risk factor for problematic alcohol use. Our findings are limited, however, by the absence of ancestry data from studies included in our analysis, precluding our ability to adjust for population stratification. Due to the likelihood of type I error in candidate gene approaches, our work highlights the critical need for studies with larger and more inclusive samples that account for sex and genetic ancestry to fully understand this relationship.

A systematic review: Candidate gene and environment interaction on alcohol use and misuse among adolescents and young adults

BACKGROUND AND OBJECTIVES

Youth drinking is a pervasive public health concern with serious negative developmental implications. Candidate gene and environment interaction studies (cGxE) show that environmental effects on drinking behaviors may differ by individuals' genotypes. Yet little is known about whether genetic and environmental effects on drinking behaviors are developmentally specific.

METHODS

This systematic review evaluated 42 cGxE studies of drinking in adolescence and young adulthood.

RESULTS

Although there are mixed findings, studies of cGxE effects involving DRD4, 5-HTTLPR, DRD2, and OPRM1 genotypes showed relatively consistent patterns. The effects of under-controlled environments (eg, low levels of parental monitoring) on early and middle adolescent drinking appeared to differ across DRD2 or OPRM1 genotypes. Effects of alcohol-facilitating environments (eg, heavy drinking peers) on late adolescent and young adult drinking appeared to differ across DRD4 or OPRM1 genotypes. Interactions between 5-HTTLPR genotype with stressful environments (eg, negative life events) were found throughout adolescence and young adulthood, although there were some inconsistencies regarding the risk-conferring allele. There was limited evidence for other cGxE effects due to the small number of studies.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

This review suggests that GxE findings may advance our knowledge regarding which developmentally specific conditions result in the expression of candidate genes that influence youth alcohol use and misuse. However, since a significant number of studies had small sample sizes and most studies had small effect sizes, findings need replication across independent studies with large samples. (Am J Addict 2018;XX:1-19).

Transactions Between Substance Use Intervention, the Oxytocin Receptor (OXTR) Gene, and Peer Substance Use Predicting Youth Alcohol Use

This study investigated the oxytocin receptor (OXTR) gene's moderation of associations between exposure to a substance misuse intervention, average peer substance use, and adolescents' own alcohol use during the 9th-grade. OXTR genetic risk was measured using five single nucleotide polymorphisms (SNPs), and peer substance use was based on youths' nominated closest friends' own reports of alcohol, cigarette, and marijuana use, based on data from the PROSPER project. Regression models revealed several findings. First, low OXTR risk was linked to affiliating with friends who reported less substance use in the intervention condition but not the control condition. Second, affiliating with high substance-using friends predicted youth alcohol risk regardless of OXTR risk or intervention condition. Third, although high OXTR risk youth in the intervention condition who associated with low substance-using friends reported somewhat higher alcohol use than comparable youth in the control group, the absolute level of alcohol use among these youth was still among the lowest in the sample.

Adolescent Social Anxiety and Substance Use: The Role of Susceptibility to Peer Pressure

The aim of this study was to further our understanding of the link between social anxiety and substance use in adolescents, in particular the role susceptibility to peer pressure plays in this link. The relation between social anxiety and susceptibility to peer pressure was studied in two community samples (n=534 and n=117) each consisting of two age groups (12-13 and 15–17 years). The relation of these two variables with substance use was evaluated in the second sample using regression analysis. Social anxiety was related to susceptibility to peer pressure in both groups and not related to substance use in the younger group and negatively related to substance use in the older group. Susceptibility to peer pressure acted as a suppressor in the relation between social anxiety and substance use. Results suggest that socially anxious adolescents basically avoid substance use but, if susceptible, may yield to peer pressure and start using substances. Parents, teachers, and therapists should be aware of this susceptibility to possibly negative peer pressure of socially anxious adolescents.