Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2,907 cases with AN from 14 countries (15 sites) and 14,860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery datasets. Seventy-six (72 independent) SNPs were taken forward for in silico (two datasets) or de novo (13 datasets) replication genotyping in 2,677 independent AN cases and 8,629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication datasets comprised 5,551 AN cases and 21,080 controls. AN subtype analyses (1,606 AN restricting; 1,445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01×10-7) in SOX2OT and rs17030795 (P=5.84×10-6) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76×10-6) between CUL3 and FAM124B and rs1886797 (P=8.05×10-6) near SPATA13. Comparing discovery to replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4×10-6), strongly suggesting that true findings exist but that our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.
anorexia nervosa; eating disorders; GWAS; genome-wide association study; body mass index; metabolic
The risk for drug addiction is partially heritable. Genes of the dopamine system are likely candidates to harbor risk variants, as dopamine neurotransmission is involved in mediating the rewarding effects of drugs of abuse. One functional SNP in DRD2, rs1076560, is involved in regulating splicing of the gene and alters the ratio of DRD2 isoforms located pre and post-synaptically. rs1076560 has been previously associated with cocaine abuse and we set out to confirm this association in a sample of European American (n=336) and African American (n=1034) cocaine addicts and European American (n=656) and African American (n=668) controls. We also analysed the role of rs1076560 in opioid dependence by genotyping European American (n=1041) and African American (n=284) opioid addicts. rs1076560 was found to be nominally associated with opioid dependence in European Americans (p=0.02, OR=1.27) and African Americans (p=0.03, OR=1.43). When both opioid addicted ancestral samples were combined, rs1076560 was significantly associated with increased risk for drug dependence (p=0.0038, OR=1.29). This association remained significant after correction for multiple testing. No association was found with cocaine dependence. These data demonstrate the importance of dopamine gene variants in the risk for opioid dependence and highlight a functional polymorphism which warrants further study.
dopamine; genetics; drug addiction; rs1076560; DRD2
Animal studies indicate gonadal hormones at puberty have an effect on the development of masculine and feminine traits. However, it is unknown whether similar processes occur in humans. We examined whether women with anorexia nervosa (AN), who often experience primary amenorrhea, exhibit attenuated feminization in their psychological characteristics in adulthood due to the decrease/absence of gonadal hormones at puberty. Women with AN were compared on a number of psychological characteristics using General Linear Models based on the presence/absence of primary amenorrhea. Although women with primary amenorrhea exhibited lower anxiety scores than those without primary amenorrhea, in general, results did not provide evidence of attenuated feminization in women with AN with primary amenorrhea. Future research should utilize novel techniques and direct hormone measurement to explore the effects of pubertal gonadal hormones on masculine and feminine traits.
Organizational effects; sex differences; amenorrhea; pubertal timing; anorexia nervosa
Two commonly prescribed treatments for opioid addiction are methadone and buprenorphine. While these drugs show some efficacy in treating opioid dependence, treatment response varies among individuals. It is likely that genetic factors play a role in determining treatment outcome. This study analyses the pharmacogenetic association of 6 polymorphisms in OPRD1, the gene encoding the delta-opioid receptor, on treatment outcome in 582 opioid addicted European Americans randomized to either methadone or buprenorphine/naloxone ((Suboxone®) over the course of a 24 week open-label clinical trial. Treatment outcome was assessed as the number of missed or opioid positive urine drug screens over the 24 weeks. In the total sample, no SNPs in OPRD1 were significantly associated with treatment outcome in either treatment arm. However, sex-specific analyses revealed 2 intronic SNPs (rs581111 and rs529520) that predicted treatment outcome in females treated with buprenorphine. Females with the AA or AG genotypes at rs581111 had significantly worse outcomes than those with the GG genotype when treated with buprenorphine (p=0.03, RR=1.67, 95% C.I.[1.06-2.1]). For rs529520, females with the AA genotype had a significantly worse outcome than those with the CC genotype when (p=0.006, RR=2.15, 95%C.I.[1.3-2.29]). No significant associations were detected in males. These findings suggest that rs581111 and rs52920 may be useful when considering treatment options for female opioid addicts, however confirmation in an independent sample is warranted.
Opioids; methadone; buprenorphine; OPRD1; pharmacogenetics; females
Although buprenorphine and methadone are both effective treatments for opioid dependence, their efficacy can vary significantly among patients. Genetic differences may explain some of the variability in treatment outcome. Understanding the interactions between genetic background and pharmacotherapy may result in more informed treatment decisions. This study is a pharmacogenetic analysis of the effects of genetic variants in OPRD1, the gene encoding the δ-opioid receptor, on the prevalence of opioid-positive urine tests in African-Americans (n=77) or European-Americans (n=566) undergoing treatment for opioid dependence. Patients were randomly assigned to treatment with either methadone or buprenorphine/naloxone (Suboxone) over a 24-week open-label clinical trial, in which illicit opioid use was measured by weekly urinalysis. In African-Americans, the intronic SNP rs678849 predicted treatment outcome for both medications. Methadone patients with the CC genotype were less likely to have opioid-positive urine tests than those in the combined CT and TT genotypes group (relative risk (RR)=0.52, 95% confidence interval (CI)=0.44–0.60, p=0.001). In the buprenorphine treatment group, however, individuals with the CC genotype were more likely to have positive opioid drug screens than individuals in the combined CT and TT genotypes group (RR=2.17, 95% CI=1.95–2.68, p=0.008). These findings indicate that the genotype at rs678849 predicts African-American patient response to two common treatments for opioid dependence, suggesting that matching patients to treatment type based on the genotype at this locus may improve overall treatment efficacy. This observation requires confirmation in an independent population.
Pharmacogenetics; Pharmacogenomics; opioids; addiction & substance abuse; psychopharmacology; methadone; buprenorphine; treatment outcome; pharmacogenetics; methadone; buprenorphine; treatment outcome.
Previous studies of prognostic factors of anorexia nervosa (AN) course and recovery have followed clinical populations after treatment discharge. This retrospective study examined the association between prognostic factors—eating disorder features, personality traits, and psychiatric comorbidity—and likelihood of recovery in a large sample of women with AN participating in a multi-site genetic study. The study included 680 women with AN. Recovery was defined as the offset of AN symptoms if the participant experienced at least one year without any eating disorder symptoms of low weight, dieting, binge eating, and inappropriate compensatory behaviors. Participants completed a structured interview about eating disorders features, psychiatric comorbidity, and self-report measures of personality. Survival analysis was applied to model time to recovery from AN. Cox regression models were used to fit associations between predictors and the probability of recovery. In the final model, likelihood of recovery was significantly predicted by the following prognostic factors: vomiting, impulsivity, and trait anxiety. Self-induced vomiting and greater trait anxiety were negative prognostic factors and predicted lower likelihood of recovery. Greater impulsivity was a positive prognostic factor and predicted greater likelihood of recovery. There was a significant interaction between impulsivity and time; the association between impulsivity and likelihood of recovery decreased as duration of AN increased. The anxiolytic function of some AN behaviors may impede recovery for individuals with greater trait anxiety.
Eating disorders; anorexia nervosa; recovery; prognostic factors; personality; comorbidity
The opioid receptor family is involved in the development and maintenance of drug addiction. The mu-opioid receptor (MOR) mediates the rewarding effects of multiple drugs, including opiates and cocaine. A number of proteins interact with MOR, potentially modulating MOR function and altering the physiological consequences of drug use. These mu-opioid receptor interacting proteins (MORIPs) are potential therapeutic targets for the treatment of addiction. The Wntless (WLS) protein was recently identified as a MORIP in a yeast two-hybrid screen. In this study, we conducted a case-control association analysis of 16 WLS genetic variants in opioid and cocaine addicted individuals of both African-American (opioid n=336, cocaine n=908) and European-American (opioid n=335, cocaine n=336) ancestry. Of the analyzed SNPs, 3 were nominally associated with opioid addiction and 4 were nominally associated with cocaine addiction. None of these associations were significant following multiple testing correction. These data suggest that the common variants of WLS analyzed in this study are not associated with opioid or cocaine addiction. However, this study does not exclude the possibilities that rare variants in WLS may affect susceptibility to drug addiction, or that common variants with small effect size may fall below the detection level of our analysis.
drug addiction; cocaine addiction; opioid addiction; genetics
The μ-opioid receptor (MOR) binds exogenous and endogenous opioids and is known to mediate the rewarding effects of drugs of abuse. Numerous genetic studies have sought to identify common genetic variation in the gene encoding MOR (OPRM1) that affects risk for drug addiction. The purpose of this study was to examine the contribution of rare coding variants in OPRM1 to the risk for addiction. Rare and low frequency variants were selected using the National Heart Lung and Blood Institute –Exome Sequencing Project (NHLBI-ESP) database, which has screened the exomes of over 6500 individuals. Two SNPs (rs62638690 and rs17174794) were selected for genotyping in 1377 European American individuals addicted to heroin and/or cocaine. Two different SNPs (rs1799971 and rs17174801) were genotyped in 1238 African American individuals addicted to heroin and/or cocaine. Using the minor allele frequencies from the NHLBI-ESP dataset as a comparison group, case-control association analyses were performed. Results revealed an association between rs62638690 and cocaine and heroin addiction in European Americans (p=0.02; 95% C.I. 0.47 [0.24–0.92]). This study suggests a potential role for rare OPRM1 variants in addiction disorders and highlights an area worthy of future study.
OPRM1; addiction; cocaine; heroin; rare variants; genetics
Women with eating disorders have a significantly higher prevalence of substance use disorders than the general population. The goal of the current study was to assess the temporal pattern of comorbid anorexia nervosa (AN) and alcohol use disorder (AUD) and the impact this ordering has on symptomatology and associated features. Women were placed into one of three groups based on the presence or absence of comorbid AUD and the order of AN and AUD onset in those with both disorders: (1) AN Only, (2) AN First, and (3) AUD First. The groups were compared on psychological symptoms and personality characteristics often associated with AN, AUD, or both using general linear models. Twenty-one percent of women (n = 161) with AN reported a history of AUD with 115 reporting AN onset first and 35 reporting AUD onset first. Women with binge-eating and/or purging type AN were significantly more likely to have AUD. In general, differences were found only between women with AN Only and women with AN and AUD regardless of order of emergence. Women with AN and AUD had higher impulsivity scores and higher prevalence of depression and borderline personality disorder than women with AN Only. Women with AN First scored higher on traits commonly associated with AN, whereas women with comorbid AN and AUD displayed elevations in traits more commonly associated with AUD. Results do not indicate a distinct pattern of symptomatology in comorbid AN and AUD based on the temporal sequence of the disorders.
anorexia nervosa; alcohol use disorder; comorbidity; age of onset
The rewarding properties of drugs of abuse are mediated by the Mu-Opioid Receptor (MOR). Genetic variation in MOR and MOR interacting proteins (MORIPs) involved in MOR signaling may increase risk for drug dependence. The MORIP, B-arrestin, plays an important role in the regulation of MOR trafficking thereby highlighting it as a candidate gene for addiction phenotypes. In this case-control association study, DNA samples from cocaine (n=336) and opioid-dependent (n=335) patients and controls (n=656) were genotyped for 7 single nucleotide polymorphisms (SNPs) (rs11868227, rs3786047, rs4522461, rs1045280, rs2271167, rs2036657, and rs4790694) across ARRB2, the gene encoding the B-arrestin 2 protein. No significant differences were observed in genotype or allele frequency between drug dependent and control individuals for any of the SNPs analyzed. Haplotype analysis was similarly negative. Further studies are needed to determine whether variation in ARRB2 (or other MORIPs) are relevant to cocaine or opioid dependence in different ethnic populations or if they confer risk that is specific to dependence on other drugs of abuse.
case-control association study; cocaine dependence; opioid dependence; AARB2
Genes involved in drug reward pathways are plausible candidates for susceptibility to substance use disorders. Given the prominent role of dopamine in drug reward, dopamine receptor-interacting proteins (DRIPs) such as the neuronal calcium sensor-1 (NCS-1) protein have been hypothesized to play a role in the pathophysiology of cocaine addiction (CA). In this study, we investigated whether genetic variants in the NCS-1 gene confer risk to CA. We genotyped 8 SNPs (rs4837479, rs7849345, rs3824544, rs10819611, rs947513, rs2277200, rs7873936 and rs1342043) in our discovery sample (cases n = 796, controls n = 416) of African descent. Confirmation of associated or trending SNPs (rs7849345, rs10819611, rs1342043) was attempted using a replication sample of African American (AA) ethnicity (cases n = 335, controls n = 336) and European-American (EA) ancestry (cases n = 336, controls n = 656). Secondary sex specific analysis was also carried out for each SNP in both AA and EA individuals. Genotyping of the discovery cohort showed significant genotypic (p = 0.0005, corrected q-value) as well as allelic (p = 0.005, corrected q-value) associations of rs1342043 with CA in AAs; however, this marker could not be confirmed in either the AA or EA replication sample. Combined analysis of all AA samples (n = 1883) for rs1342043 showed a significant association with CA (genotypic p = 0.0001, allelic p = 0.002) with a gender specific effect for males (allelic p = 0.005, genotypic p = 0.0003). Our data suggest that genetic variants in the NCS-1 gene contribute to susceptibility of CA in individuals of African descent.
Addiction; Cocaine; NCS-1; African Americans; European Americans
BALB/cJ and C57BL/6J inbred mouse strains have been proposed as useful models of low and high levels of sociability (tendency to seek social interaction), respectively, based primarily on behaviors of ~30-day-old mice in the Social Approach Test (SAT). In the SAT, approach and sniffing behaviors of a test mouse toward an unfamiliar stimulus mouse are measured in a novel environment. However, it is unclear whether such results generalize to a familiar environment with a familiar social partner, such as with a littermate in a home cage environment. We hypothesized that C57BL/6J mice would show higher levels of social behaviors than BALB/cJ mice in the home cage environment, particularly at 30 days-of-age. We measured active and passive social behaviors in home cages by pairs of BALB/cJ or C57BL/6J littermates at ages 30, 41, and 69 days. The strains did not differ robustly in their active social behaviors. C57BL/6J mice were more passively social than BALB/cJ mice at 30 days, and C57BL/6J levels of passive social behaviors declined to BALB/cJ levels by 69 days. The differences in passive social behaviors at 30 days-of-age were primarily attributable to differences in huddling. These results indicate that different test conditions (SAT conditions vs. home cage conditions) elicit strain differences in distinct types of behaviors (approach/sniffing vs. huddling behaviors, respectively). Assessment of the more naturalistic social interactions in the familiar home cage environment with a familiar littermate will provide a useful component of a comprehensive assessment of social behaviors in mouse models relevant to autism.
mouse; social; behavior; development; genetic; environment
Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2,907 cases with AN from 14 countries (15 sites) and 14,860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery datasets. Seventy-six (72 independent) SNPs were taken forward for in silico (two datasets) or de novo (13 datasets) replication genotyping in 2,677 independent AN cases and 8,629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication datasets comprised 5,551 AN cases and 21,080 controls. AN subtype analyses (1,606 AN restricting; 1,445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01×10−7) in SOX2OT and rs17030795 (P=5.84×10−6) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76×10−6) between CUL3 and FAM124B and rs1886797 (P=8.05×10−6) near SPATA13. Comparing discovery to replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P= 4×10−6), strongly suggesting that true findings exist but that our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.
anorexia nervosa; eating disorders; GWAS; genome-wide association study; body mass index; metabolic
Genetic research on cocaine dependence may help clarify our understanding of the disorder as well as provide insights for effective treatment. Since endocannabinoid signaling and dopamine neurotransmission have been shown to be involved with drug reward, genes related to these systems are plausible candidates for susceptibility to cocaine dependence. The cannabinoid receptor 1 (CB1) protein regulates both the endocannabinoid and dopaminergic neurobiological systems, and polymorphisms in the cannabinoid receptor gene, CNR1, have been previously been associated with substance dependence. In this study, we attempt to replicate a finding associating CNR1 with cocaine dependence in African Americans. Cocaine dependent individuals (n=883) and unaffected controls (n=334) of African descent were genotyped for two single nucleotide polymorphisms (SNPs) in the CB1 gene (rs6454674, rs806368). We observed a significant difference in genotype frequencies between cases and controls for both SNPs (p≤0.05). This study confirms the association between variants in the CNR1 and cocaine dependence. However, considering the substantial co-morbidity of cocaine dependence with other drugs of abuse, additional studies are necessary to determine whether polymorphisms in CNR1 induce a general susceptibility to substance dependence or are specific to cocaine addiction.
Addiction; Association study; Cocaine; Cannabinoid receptor; Genetics; Substance abuse
We studied the relation between intrusive and repetitive hair-pulling, the defining feature of trichotillomania, and compulsive and impulsive features in 1453 individuals with anorexia nervosa and bulimia nervosa. We conducted a series of regression models examining the relative influence of compulsive features associated with obsessive compulsive disorder; compulsive features associated with eating disorders; trait features related to harm avoidance, perfectionism and novelty seeking; and self harm. A final model with a reduced sample (n=928) examined the additional contribution of impulsive attributes. One out of 20 individuals endorsed hair-pulling. Evidence of a positive association with endorsement of compulsive behavior of the obsessive compulsive spectrum emerged. Hair-pulling may be more consonant with ritualistic compulsions than impulsive urges in those with eating disorders.
eating disorders; trichotillomania; hair-pulling; anorexia nervosa; bulimia nervosa; impulsivity; compulsivity
To further refine our understanding of impulsivity, obsessions, and compulsions in anorexia nervosa (AN) by isolating which behaviors—binge eating, purging, or both—are associated with these features.
We conducted regression analyses with binge eating, purging, and the interaction of binge eating with purging as individual predictors of scores for impulsivity, obsessions, and compulsions in two samples of women with AN (n = 1373).
Purging, but not binge eating, was associated with higher scores of impulsivity, obsessions and compulsions. Purging was also associated with worst eating rituals and with worst eating preoccupations.
Our results suggest that purging, compared with binge eating, may be a stronger correlate of impulsivity, obsessions, and compulsions in AN.
anorexia nervosa; impulsivity; compulsivity; binge eating; purging
Sociability—the tendency to seek social interaction–propels the development of social cognition and social skills, but is disrupted in autism spectrum disorders (ASD). BALB/cJ and C57BL/6J inbred mouse strains are useful models of low and high levels of juvenile sociability, respectively, but the neurobiological and developmental factors that account for the strains’ contrasting sociability levels are largely unknown. We hypothesized that BALB/cJ mice would show increasing sociability with age but that C57BL/6J mice would show high sociability throughout development. We also hypothesized that littermates would resemble one another in sociability more than non-littermates. Finally, we hypothesized that low sociability would be associated with low corpus callosum size and increased brain size in BALB/cJ mice. Separate cohorts of C57BL/6J and BALB/cJ mice were tested for sociability at 19-, 23-, 31-, 42-, or 70-days-of-age, and brain weights and mid-sagittal corpus callosum area were measured. BALB/cJ sociability increased with age, and a strain by age interaction in sociability between 31 and 42 days of age suggested strong effects of puberty on sociability development. Sociability scores clustered according to litter membership in both strains, and perinatal litter size and sex ratio were identified as factors that contributed to this clustering in C57BL/6J, but not BALB/cJ, litters. There was no association between corpus callosum size and sociability, but smaller brains were associated with lower sociability in BALB/cJ mice. The associations reported here will provide directions for future mechanistic studies of sociability development.
Autism; Mouse; Model; Juvenile; Social; Behavior
This exploratory study assessed whether maternal recall of childhood feeding and eating practices differed across anorexia nervosa (AN) subtypes. Participants were 325 women from the Genetics of Anorexia Nervosa study whose mothers completed a childhood feeding and eating questionnaire. Multinomial logistic regression analyses were used to predict AN subtype from measures related to childhood eating: (a) infant feeding (breastfed, feeding schedule, age of solid food introduction), (b) childhood picky eating (picky eating before age one and between ages one and five), and (c) infant gastrointestinal problems (vomiting and colic). Results revealed no significant differences in retrospective maternal report of childhood feeding and eating practices among AN subtypes.
Anorexia Nervosa; Anorexia Nervosa Subtype; Feeding; Maternal Report; Infancy
Comorbidity among eating disorders, traumatic events, and post traumatic stress disorder (PTSD) has been reported in several studies. The main objectives of this study were to describe the nature of traumatic events experienced and to explore the relation between PTSD and anorexia nervosa (AN) in a sample of women.
Eight hundred twenty-four participants from the National Institutes of Health funded Genetics of Anorexia Nervosa Collaborative Study were assessed for eating disorders, PTSD, and personality characteristics.
From a final sample of 753 women with AN, 13.7% (n=103) met DSM-IV criteria for PTSD. The sample mean age was 29.5 years (SD=11.1). In pairwise comparisons across AN subtypes, the odds of having a PTSD diagnosis were significantly lower in individuals with restricting AN (RAN) than individuals with purging AN without binge eating (PAN) (OR=0.49, 95% CI=0.30, 0.80). The majority of participants with PTSD reported the first traumatic event before the onset of AN (64.1%, n=66). The most common traumatic events reported by those with a PTSD diagnosis were sexual related traumas during childhood (40.8%) and during adulthood (35.0%).
AN and PTSD do co-occur and traumatic events tend to occur prior to the onset of AN. Clinically, these results underscore the importance of assessing trauma history and PTSD in individuals with AN and raise the question of whether specific modifications or augmentations to standard treatment for AN should be considered in a subgroup to address PTSD-related psychopathology.
PTSD; anorexia nervosa; trauma; prevalence; comorbid; epigenetic
Genome-wide association studies implicate variations in CHRNA5 and CHRNA3 as being associated with nicotine addiction (NA). Multiple common haplotypes (“risk”, “mixed” and “protective”) exist in Europeans; however, high linkage disequilibrium between variations in CHRNA5 and CHRNA3 makes assigning causative allele(s) for NA difficult through genotyping experiments alone. We investigated whether CHRNA5 or CHRNA3 promoter haplotypes, associated previously with NA, might influence allelic expression levels. For in vitro analyses, promoter haplotypes were sub-cloned into a luciferase reporter vector. When assessed in BE(2)-C cells, luciferase expression was equivalent among CHRNA3 haplotypes, but the combination of deletion at rs3841324 and variation at rs503464 decreased CHRNA5 promoter-derived luciferase activity, possibly due to loss of an SP-1 and other site(s). Variation within the CHRNA5 5’UTR at rs55853698 and rs55781567 also altered luciferase expression in BE(2)-C cells. Allelic expression imbalance (AEI) from the “risk” or “protective” haplotypes was assessed in post-mortem brain tissue from individuals heterozygous at coding polymorphisms in CHRNA3 (rs1051730) or CHRNA5 (rs16969968). In most cases, equivalent allelic expression was observed; however, one individual showed CHRNA5 AEI that favored the “protective” allele and that was concordant with heterozygosity at polymorphisms ∼13.5 kb upstream of the CHRNA5 transcription start site. Putative enhancer activity from these distal promoter elements was assessed using heterologous promoter constructs. We observed no differences in promoter activity from the two distal promoter haplotypes examined, but found that the distal promoter region strongly repressed transcription. We conclude that CHRNA5 promoter variants may affect relative risk for NA in some heterozygous individuals.
We investigated sociodemographic characteristics in women with and without lifetime eating disorders.
Participants were from a multi-site international study of eating disorders (N = 2096). Education level, relationship status, and reproductive status were examined across eating disorder subtypes and compared with a healthy control group.
Overall, women with eating disorders were less educated than controls, and duration of illness and age of onset were associated with educational attainment. Menstrual status was associated with both relationship and reproductive status, but eating disorder subtypes did not differ significantly from each other or from healthy controls on these dimensions.
Differences in educational attainment, relationships, and reproduction do exist in individuals with eating disorders and are differentially associated with various eating disorder symptoms and characteristics. These data could assist with educating patients and family members about long-term consequences of eating disorders.
Children; relationship; education; anorexia nervosa; bulimia nervosa; amenorrhea
Although a highly heritable and disabling disease, bipolar disorder's (BD) genetic variants have been challenging to identify. We present new genotype data for 1,190 cases and 401 controls and perform a genome-wide association study including additional samples for a total of 2,191 cases and 1,434 controls. We do not detect genome-wide significant associations for individual loci; however, across all SNPs, we show an association between the power to detect effects calculated from a previous genome-wide association study and evidence for replication (P = 1.5×10−7). To demonstrate that this result is not likely to be a false positive, we analyze replication rates in a large meta-analysis of height and show that, in a large enough study, associations replicate as a function of power, approaching a linear relationship. Within BD, SNPs near exons exhibit a greater probability of replication, supporting an enrichment of reproducible associations near functional regions of genes. These results indicate that there is likely common genetic variation associated with BD near exons (±10 kb) that could be identified in larger studies and, further, provide a framework for assessing the potential for replication when combining results from multiple studies.
Bipolar disorder (BD) is a highly heritable disease that has been difficult to characterize genetically. We have genotyped 1,190 BD cases and 401 controls to find regions of the genome associated with BD. After combining these data with previously existing genotyped samples, we did not find any genome-wide significant associations. However, when we used an additional study to prioritize loci for replication and meta-analysis purposes, we found that we were more likely to see an association in our sample with variants for which we had the highest power. We quantified this effect using logistic regression and saw a strong association between power to detect an effect based on an initial study's results and replication P-value in a second study (P = 1.5×10−7), supporting the presence of shared genetic risk factors across the studies. Moreover, this association was stronger when we restricted analysis to SNPs near coding regions, and it was further enriched when SNPs had the same direction of effect in both studies. This result supports the presence of genetic factors underlying BD near exons whose collective effect results in a detectable signal and provides a framework for assessing the potential for replication when combining results from multiple studies.