CHRNA5/A3/B4 Variant rs3743078 and Nicotine-Related Phenotypes: Indirect Effects Through Nicotine Craving.

OBJECTIVE: Nicotine craving is considered an important element in the persistence of cigarette smoking, but little is known about the role of craving in the widely recognized association between variants mapped to the neuronal nicotinic acetylcholine receptor (CHRN) genes on chromosome 15 and nicotine phenotypes. METHOD: The associations between CHRNA5-CHRNA3-CHRNB4 variants and cigarettes per day (CPD), the Fagerström Test for Nicotine Dependence (FTND), and craving were analyzed in data from 662 lifetime smokers from an Israeli adult Jewish household sample. Indirect effects of genotype on nicotine phenotypes through craving were formally tested using regression and bootstrapping procedures. RESULTS: At CHRNA3, allele G of rs3743078 was associated with increased craving, CPD, and FTND scores: Participants with one or two copies of the G allele had, on average, higher scores on the craving scale (p = .0025), more cigarettes smoked (p = .0057), and higher scores on the FTND (p =.0024). With craving in the model, variant rs3743078 showed a significant indirect effect through craving on CPD (p = .0026) and on FTND score (p = .0024). A sizeable proportion of the total rs3743078 effect on CPD (56.4%) and FTND (65.2%) was indirect through craving. CONCLUSIONS: These results suggest that nicotine craving may play a central role in nicotine use disorders and may have utility as a therapeutic target.

Thymic and bone marrow output in individuals with 22q11.2 deletion syndrome.

BACKGROUND: The 22q11.2 deletion syndrome (22q11.2DS) is a congenital multisystem anomaly characterized by typical facial features, palatal anomalies, congenital heart defects, hypocalcemia, immunodeficiency, and cognitive and neuropsychiatric symptoms. The aim of our study was to investigate T- and B-lymphocyte characteristics associated with 22q11.2DS. METHODS: Seventy-five individuals with 22q11.2DS were tested for T and B lymphocytes by examination of T-cell receptor rearrangement excision circles (TRECs) and B-cell κ-deleting recombination excision circles (KRECs), respectively. RESULTS: The 22q11.2DS individuals displayed low levels of TRECs, while exhibiting normal levels of KRECs. There was a significant positive correlation between TREC and KREC in the 22q11.2DS group, but not in controls. Both TREC and KREC levels showed a significant decrease with age and only TREC was low in 22q11.2DS individuals with recurrent infections. No difference in TREC levels was found between 22q11.2DS individuals who underwent heart surgery (with or without thymectomy) and those who did not. CONCLUSION: T-cell immunodeficiency in 22q11.2DS includes low TREC levels, which may contribute to recurrent infections in individuals with this syndrome. A correlation between T- and B-cell abnormalities in 22q11.2DS was identified. The B-cell abnormalities could account for part of the immunological deficiency seen in 22q11.2DS.

Trauma exposure, posttraumatic stress disorder and risk for alcohol, nicotine, and marijuana dependence in Israel.

BACKGROUND: Substance dependence is more common among trauma-exposed individuals; however, most studies suggest that Posttraumatic Stress Disorder (PTSD) accounts for the link between trauma exposure (TE) and substance dependence. OBJECTIVES: This study examined associations between TE and substance dependence (alcohol, nicotine, and marijuana), and whether PTSD accounted for this association. METHOD: 1317 Jewish Israeli household residents completed in-person structured interviews assessing TE, PTSD, and substance (alcohol, nicotine, marijuana) dependence between 2007 and 2009. Regression analyses examined associations among TE, PTSD, and substance dependence. RESULTS: In the full sample, mean number of traumatic events was 2.7 (sd=2.2), with 83.7% experiencing at least one event. In the full sample, mean number of PTSD symptoms was 2.5 (sd=3.4), with 13.5% meeting PTSD diagnostic criteria. Prevalence of alcohol dependence was 13.4%; nicotine dependence 52.8%; and marijuana dependence 12.1%. Number of traumatic events was associated with increased odds of alcohol (OR=1.3; 95% CI=1.2-1.4) and nicotine (OR=1.2; 95% CI=1.1-1.3) dependence. Similarly, any traumatic event exposure was associated with increased odds of alcohol (OR=3.1; 95% CI=1.6-6.0) and nicotine (OR=1.9; 95% CI=1.2-2.9) dependence. PTSD symptoms were associated with increased odds of alcohol (OR=1.2; 95% CI=1.1-1.3), nicotine (OR=1.1; 95% CI=1.1-1.2), and marijuana (OR=1.1; 95% CI=1.04-1.2) dependence; similarly, a PTSD diagnosis was associated with increased odds of alcohol (OR=3.4; 95% CI=2.1-5.5), nicotine (OR=2.2; 95% CI=1.4-3.4), and marijuana (OR=2.6; 95% CI=1.2-5.9) dependence. PTSD symptoms accounted for a sizeable proportion of the TE effect on alcohol (46%) and nicotine dependence (31%). CONCLUSION: Individuals with more traumatic events had heightened risk for alcohol and nicotine dependence, and PTSD symptoms partially accounted for this risk. However, marijuana dependence was only significantly related to PTSD symptoms. Clinicians and researchers should separately assess different types of dependence among trauma-exposed individuals both with and without PTSD symptoms.

The feasibility and safety of S-adenosyl-L-methionine (SAMe) for the treatment of neuropsychiatric symptoms in 22q11.2 deletion syndrome: a double-blind placebo-controlled trial.

The goal of this trial was to assess the feasibility and safety of using S-adenosyl-L-methionine (SAMe) to treat depressive disorder, attention deficit/hyperactivity disorder (ADHD) and cognitive deficits in individuals with the 22q11.2 deletion syndrome (22q11.2DS). SAMe supposedly enhances the activity of the COMT enzyme. Because individuals with 22q11.2DS have only one copy of the gene responsible for the enzyme, COMT haploinsufficiency may be associated with their psychiatric morbidity and cognitive deficits. We assessed twelve 22q11.2DS individuals with depressive disorder or ADHD in a randomized double-blind cross-over placebo-controlled trial, using SAMe 800 mg bid. Individuals were evaluated for treatment safety and effectiveness during the trial and upon completion at sixth week. Compared to placebo, there were no significant differences in the rate of reported side effects between SAMe and placebo. Despite a general concern that SAMe might induce mania in vulnerable individuals, no manic or psychotic symptoms were exhibited during the SAMe treatment. Individuals with 22q11.2DS with comorbid depressive disorder with or without psychotic symptoms (n = 5) had a larger numerical improvement on relevant clinical scales compared to placebo. No treatment effect was found on ADHD symptoms in subjects who suffered from 22q11.2DS with comorbid ADHD (n = 7). Cognitive performance did not improve or deteriorate following treatment with SAMe compared to placebo. In conclusion SAMe treatment up to 1,600 mg/day for 6 weeks in 22q11.2DS individuals appears to be safe, well tolerated and with no serious side effects. No significant benefit in depressive or ADHD symptoms was detected.

Nicotine dependence, abuse and craving: dimensionality in an Israeli sample.

AIMS: Evidence-based changes planned for Diagnostic and Statistical Manual 5th edition (DSM-5) substance use disorders (SUDs) include combining dependence and three of the abuse criteria into one disorder and adding a criterion indicating craving. Because DSM-IV did not include a category for nicotine abuse, little empirical support is available for aligning the nicotine use disorder criteria with the DSM-5 criteria for other SUDs. DESIGN: Latent variable analyses, bootstrap tests and likelihood ratio tests were used to explore the unidimensionality, psychometric properties and information of the nicotine criteria. SETTING AND PARTICIPANTS: A sample of household residents selected from the Israeli population register yielded 727 life-time cigarette smokers. MEASUREMENTS: DSM-IV nicotine dependence criteria and proposed abuse and craving criteria, assessed with a structured interview. FINDINGS: Three abuse criteria (hazardous use, social/interpersonal problems and neglect roles) were prevalent among smokers, formed a unidimensional latent trait with nicotine dependence criteria, were intermixed with dependence criteria across the severity spectrum and significantly increased the diagnostic information over the dependence-only model. A craving criterion was shown to fit well with the other criteria. CONCLUSION: Similar to findings from research on other substances, nicotine dependence, abuse and craving criteria appear to derive from a common underlying dimension. The results support alignment of nicotine criteria with those for alcohol and drug use disorders in Diagnostic and Statistical Manual 5th edition.

Association of tetralogy of Fallot with a distinct region of del22q11.2.

Congenital heart defects (CHDs) appear in greater frequency among relatives of patients and in individuals with DiGeorge syndrome (DGS) or velo-cardio-facial syndrome (VCFS). A majority of these patients and part of the apparently nonsyndromic CHD patients with conotruncal defects manifest hemizygous deletions within chromosome 22q11.2 (del22q11). We tested myocardial tissues of 31 CHD patients, 21 with tetralogy of Fallot (TOF) and 10 with a double-chamber right ventricle (DCRV). DNA isolated from tissues removed at corrective surgery was analyzed for homo- or heterozygosity of nine polymorphic short tandem repeat (STR) markers along the 22q11.2 region. DNA from the blood of 45 healthy individuals represented the general population. Ten of the 21 TOF patients (48%) showed homozygosity for three or more consecutive markers, indicating deletions of various sizes. No such indication was found for DCRV patients. Heterozygosity for markers D22S1648, D22S941, and D22S944 was lower in the TOF group than in normal controls, defining a minimal critical region (MCR) for the deletion. Our findings support an association between TOF and hemizygosity in 22q11.2, suggesting a distinct region, between markers D22S1638 and COMT, that may harbor TOF susceptibility genes.

Heritability, genetics and association findings in anorexia nervosa.

Anorexia nervosa (AN) is a severe psychiatric disorder, characterized by a combination of abnormal eating behavior and weight regulation with disturbances of attitudes toward body weight and shape. Prevalence is estimated at 1/1000, but with a high prevalence of the partial syndrome and a 10% mortality rate. This article reviews the findings concerning the heritability and the contributing genes of the disorder, with a focus on candidate genes. In family studies, a higher frequency of AN and BN was found among relatives of AN probands. The heritability rate was estimated at 0.71, similar to twin studies, which estimate 0.58-0.76. The search for genes responsible for the disorder focuses on the monoaminergic and peptidergic systems that are related to appetite and weight regulation. So far, for serotonin and dopamine there are no consistent findings in association studies of AN. However, in an Israeli study, an association was found between susceptibility for AN and the COMT gene, which is involved in monoamine metabolism. Another Israeli study found a relation between AN and the gene encoding for the potassium channel (hSKCa3), which is involved in regulation of neuronal activity. In the endocrine system an unequivocal finding was described of an association to the gene encoding the receptor for beta-estrogen. In the appetite and weight regulation system an association was described between AN and a marker of the uncoupling protein-2 and -3 chromosomal region, raising the likelihood that the mutation within the gene is close to a positive marker. To conclude, although there is a strong familial component in AN, so far the search for candidate genes has not been fruitful and further large scale prospective and adoption studies are needed to confirm genetic factors. We hope that relative studies using a wide genome scan, as well as subtyping the different types of AN, will bring us closer to understanding of the heritability of AN and enable the development of improved means of prevention and treatment.