Rare and Common Variants Conferring Risk of Tooth Agenesis.

We present association results from a large genome-wide association study of tooth agenesis (TA) as well as selective TA, including 1,944 subjects with congenitally missing teeth, excluding third molars, and 338,554 controls, all of European ancestry. We also tested the association of previously identified risk variants, for timing of tooth eruption and orofacial clefts, with TA. We report associations between TA and 9 novel risk variants. Five of these variants associate with selective TA, including a variant conferring risk of orofacial clefts. These results contribute to a deeper understanding of the genetic architecture of tooth development and disease. The few variants previously associated with TA were uncovered through candidate gene studies guided by mouse knockouts. Knowing the etiology and clinical features of TA is important for planning oral rehabilitation that often involves an interdisciplinary approach.

Increased expression of BIN1 mediates Alzheimer genetic risk by modulating tau pathology.

Genome-wide association studies (GWAS) have identified a region upstream the BIN1 gene as the most important genetic susceptibility locus in Alzheimer's disease (AD) after APOE. We report that BIN1 transcript levels were increased in AD brains and identified a novel 3 bp insertion allele ∼28 kb upstream of BIN1, which increased (i) transcriptional activity in vitro, (ii) BIN1 expression levels in human brain and (iii) AD risk in three independent case-control cohorts (Meta-analysed Odds ratio of 1.20 (1.14-1.26) (P=3.8 × 10(-11))). Interestingly, decreased expression of the Drosophila BIN1 ortholog Amph suppressed Tau-mediated neurotoxicity in three different assays. Accordingly, Tau and BIN1 colocalized and interacted in human neuroblastoma cells and in mouse brain. Finally, the 3 bp insertion was associated with Tau but not Amyloid loads in AD brains. We propose that BIN1 mediates AD risk by modulating Tau pathology.

Genome-wide association scan for childhood caries implicates novel genes.

Dental caries is the most common chronic disease in children and a major public health concern due to its increasing incidence, serious health and social co-morbidities, and socio-demographic disparities in disease burden. We performed the first genome-wide association scan for dental caries to identify associated genetic loci and nominate candidate genes affecting tooth decay in 1305 US children ages 3-12 yrs. Affection status was defined as 1 or more primary teeth with evidence of decay based on intra-oral examination. No associations met strict criteria for genome-wide significance (p < 10E-7); however, several loci (ACTN2, MTR, and EDARADD, MPPED2, and LPO) with plausible biological roles in dental caries exhibited suggestive evidence for association. Analyses stratified by home fluoride level yielded additional suggestive loci, including TFIP11 in the low-fluoride group, and EPHA7 and ZMPSTE24 in the sufficient-fluoride group. Suggestive loci were tested but not significantly replicated in an independent sample (N = 1695, ages 2-7 yrs) after adjustment for multiple comparisons. This study reinforces the complexity of dental caries, suggesting that numerous loci, mostly having small effects, are involved in cariogenesis. Verification/replication of suggestive loci may highlight biological mechanisms and/or pathways leading to a fuller understanding of the genetic risks for dental caries.

Identification of rosmarinic acid as the major active constituent in Cordia americana.

ETHNOPHARMACOLOGICAL RELEVANCE: Preparation from leaves of Cordia americana have been widely used in traditional medicine in South Brazil to treat wounds and various inflammations. AIM OF THE STUDY: The objective of this work was to identify the effective compounds in the ethanolic extract prepared from the leaves of Cordia americana, which is used in traditional South Brazilian medicine as anti-inflammatory and wound healing remedy. MATERIALS AND METHODS: Isolation and structure elucidation techniques were performed in order to identify the compounds of Cordia americana and HPLC analysis was used for the quantification. The major constituent and the ethanolic extract were investigated for inhibition of 5-lipoxygenase, p38alpha MAPK, TNFalpha release and NF-kappaB as well as in the fibroblast scratch assay. RESULTS: Rosmarinic acid (1) was identified as the major compound with an amount of 8.44% in the ethanolic extract of the leaves of Cordia americana. The ethanolic extract as well as (1) exhibited the highest inhibitory effects on 5-lipoxygenase (IC(50)=0.69 and 0.97microg/mL, resp., IC50 of BWA4C as reference: 0.3microM) and p38alpha (IC50=3.25 and 1.16microg/mL, resp., IC50 of SB203580 as reference: 0.046microM) and moderate inhibitory effects on TNFalpha release. Slight effects were observed in the fibroblast scratch assay. CONCLUSIONS: This study increases our knowledge on the effective compound in Cordia americana and supports its use in traditional medicine. We demonstrated for the first time pharmacological effects of Cordia americana and we provide evidences for a crucial role of rosmarinic acid as the major key player.

Biological studies on Brazilian plants used in wound healing.

AIM OF THE STUDY: n-Hexanic and ethanolic extracts from twelve plants (Brugmansia suaveolens Brecht. et Presl., Eupatorium laevigatum Lam., Galinsoga parviflora Cav., Iresine herbstii Hook., Kalanchöe tubiflora Hamet-Ahti, Petiveria alliacea L., Pluchea sagittalis (Lam.) Cabrera, Piper regnellii DC., Schinus molle L., Sedum dendroideum Moç et Sessé ex DC., Waltheria douradinha St. Hill., Xanthium cavanillesii Schouw.) used in traditional South Brazilian medicine as wound healing agents were investigated in various biological assays, targeting different aspects in this complex process. MATERIALS AND METHODS: The extracts were investigated on NF-kappaB DNA binding, p38alpha MAPK, TNF-alpha release, direct elastase inhibition and its release as well as on caspase-3. Fibroblasts migration to and proliferation into the wounded monolayers were evaluated in the scratch assay, the agar diffusion test for antibacterial and the MTT assay for cytotoxic effects. RESULTS: The hydrophilic extracts from Galinsoga parviflora, Petiveria alliacea, Schinus molle, Waltheria douradinha and Xanthium cavanillesii as well as the lipophilic extract of Waltheria douradinha turned out to be the most active ones. CONCLUSIONS: These results increase our knowledge on the wound healing effects of the investigated medicinal plants. Further studies are necessary to find out the effective secondary metabolites responsible for the observed effects.

[Occupational and non-occupational risk factors in bladder cancer patients in an industrialized area located in former East-Germany]. / Berufliche und ausserberufliche Risikofaktoren für das Harnblasenkarzinom in einem ehemaligen Industriegebiet der neuen Bundesländer.

PURPOSE: Several occupational carcinogens are metabolized by polymorphic enzymes. The distribution of the polymorphic enzymes N-acetyltransferase 2 (NAT2; substrates: aromatic amines), glutathione S-transferase M1 (GSTM1; substrates: e. g., reactive metabolites of polycyclic aromatic hydrocarbons), and glutathione S-transferase T1 (GSTT1; substrates: small molecules with 1 - 2 carbon atoms) were investigated. MATERIAL AND METHODS: At the urological department in Lutherstadt Wittenberg, 136 patients with a histologically proven transitional cell cancer of the urinary bladder were investigated for all occupations performed for more than 6 months. Several occupational and non-occupational risk factors were asked. The genotypes of NAT2, GSTM1, and GSTT1 were determined from leucocyte DNA by PCR. RESULTS: Compared to the general population in Middle Europe, the percentage of GSTT1 negative persons (22.1 %) was ordinary; the percentage of slow acetylators (59.6 %) was in the upper normal range, while the percentage of GSTM1 negative persons (58.8 %) was elevated in the entire group. Shifts in the distribution of the genotypes were observed in subgroups who had been exposed to asbestos (6/6 GSTM1 negative, 5/6 slow acetylators), rubber manufacturing (8/10 GSTM1 negative), and chlorinated solvents (9/15 GSTM1 negative). CONCLUSIONS: The overrepresentation of GSTM1 negative bladder cancer patients also in this industrialized area and more pronounced in several occupationally exposed subgroups points to an impact of the GSTM1 negative genotype in bladder carcinogenesis.

Association of the 103I MC4R allele with decreased body mass in 7937 participants of two population based surveys.

BACKGROUND: The melanocortin-4-receptor gene (MC4R) is part of the melanocortinergic pathway that controls energy homeostasis. In a recent meta-analysis, the MC4R V103I (rs2229616) polymorphism was shown to be associated with body weight regulation. Although no functional differences between the isoleucine comprising receptor and the wild type receptor have been detected as yet, this meta-analysis of 14 case-control studies reported a mild negative association with obesity (odds ratio (OR) 0.69, p = 0.03). However, evidence in a large population based study in a homogeneous population and a significant estimate of the change in quantitative measures of obesity is still lacking. METHODS: We analysed the data of two surveys of a white population with the same high quality study protocol, giving a total of 7937 participants. RESULTS: By linear regression, we found a significant decrease of 0.52 body mass index (BMI) units (95% confidence interval (CI) -0.02 to -1.03, p = 0.043) for carriers of the heterozygote rs2229616G/A genotype, which was observed in 3.7% of the participants. Logistic regression yielded a significantly negative association of the MC4R variant with "above average weight" (BMI > or = median BMI) yielding an OR of 0.75 (95% CI 0.59 to 0.95 p = 0.017). We obtained similar results comparing obese (BMI > or =30 kg/m2, World Health Organization results for 1997) with non-obese (BMI < 30 kg/m2) participants. The results were found for both sexes and each survey separately, and did not depend on the modelling of age, sex, or survey effects. CONCLUSIONS: Our study confirms previous findings of a meta-analysis that the relatively infrequent G/A genotype of the V103I MC4R polymorphism is negatively associated with above average weight and obesity in population based original data of 7937 participants, and extends previous findings by showing for the first time a significantly lower BMI in individuals carrying the infrequent allele of this MC4R variant.

Mutation screen of the brain derived neurotrophic factor gene (BDNF): identification of several genetic variants and association studies in patients with obesity, eating disorders, and attention-deficit/hyperactivity disorder.

Several lines of evidence indicate an involvement of brain derived neurotrophic factor (BDNF) in body weight regulation and activity: heterozygous Bdnf knockout mice (Bdnf(+/-)) are hyperphagic, obese, and hyperactive; furthermore, central infusion of BDNF leads to severe, dose-dependent appetite suppression and weight loss in rats. We searched for the role of BDNF variants in obesity, eating disorders, and attention-deficit/hyperactivity disorder (ADHD). A mutation screen (SSCP and DHPLC) of the translated region of BDNF in 183 extremely obese children and adolescents and 187 underweight students was performed. Additionally, we genotyped two common polymorphisms (rs6265: p.V66M; c.-46C > T) in 118 patients with anorexia nervosa, 80 patients with bulimia nervosa, 88 patients with ADHD, and 96 normal weight controls. Three rare variants (c.5C > T: p.T2I; c.273G > A; c.*137A > G) and the known polymorphism (p.V66M) were identified. A role of the I2 allele in the etiology of obesity cannot be excluded. We found no association between p.V66M or the additionally genotyped variant c.-46C > T and obesity, ADHD or eating disorders. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299:1/suppmat/index.html.

Transmission disequilibrium studies in children and adolescents with obsessive-compulsive disorders pertaining to polymorphisms of genes of the serotonergic pathway.

Pharmacological and challenge study data showed an involvement of the serotonergic system in the development of obsessive-compulsive disorder (OCD). We studied transmission disequilibrium of polymorphisms in three candidate genes of the serotonergic pathway in 64 trios comprising patients with early onset OCD and both of their parents. Polymorphisms of the following genes were studied: tryptophan hydroxylase 1 (rs1800532), serotonin transporter (polymorphism in the promoter region; 5-HTTLPR) and the serotonin 1 B receptor (rs6296). This is, to our knowledge, one of the first family based association studies pertaining to children and adolescents with OCD. We did not detect transmission disequilibrium of the investigated polymorphisms in OCD. Hence, these polymorphisms do not play a major role in the genetic predisposition to early onset OCD.

Binge-eating episodes are not characteristic of carriers of melanocortin-4 receptor gene mutations.

Recently, Branson and coworkers reported a strong association between binge-eating disorder (BED) and variants in the melanocortin-4 receptor gene (MC4R). In the current study, we compared the eating behavior of 43 obese probands with functionally relevant MC4R mutations and of 35 polymorphism carriers (V103I or I251L) with wild-type carriers. The module for eating disorders of the Composite International Diagnostic Interview was used to identify binge-eating behavior. The Three-Factor Eating Questionnaire and the Leeds Food Frequency Questionnaire were used to assess restrained eating, disinhibition, hunger and percent total energy intake as fat. No significant differences between carriers of MC4R variants and wild-type carriers were detected. In particular, we found no evidence for an increased rate of binge-eating behavior in obese carriers of MC4R variants. Our findings do not support the strong association between BED and MC4R carrier status.

Combined family trio and case-control analysis of the COMT Val158Met polymorphism in European patients with anorexia nervosa.

The high activity Val158 (H) allele of the dopamine-metabolizing enzyme catechol-O-methyltransferase (COMT) was associated with anorexia nervosa (AN) in a recent family trio-based study of patients from Israel. In an attempt to replicate this finding, we performed a combined family trio and case-control study in an European population from seven centers in six different countries (Austria, Germany, Great Britain, Italy [Milan], Italy [Florence], Slovenia, and Spain), together contributing a total of 372 family trios, 684 controls and 266 cases. TDT analyses of high (H) and low (L) alleles in family trios showed that H allele and L allele were each transmitted 101 times (chi(2) = 0, ns). Allele-wise case-control analysis using separate samples simply combined from the centers was also not significant, with the frequencies of the H allele 50% in cases and same in controls. Stratified analysis of data from all centers gave an odds ratio of 0.98 (Cornfield 95% confidence limits 0.78-1.24). Analysis by genotype was likewise not significant (overall chi(2) = 0.42). Because we were not able to support the primary hypothesis that Val158Met is a risk factor for AN, we did not perform secondary analysis of minimum body mass index (mBMI), age at onset or illness subtype (restricting or binge purging anorexia). Overall we found no support for the hypothesis that the Val158 allele of COMT gene is associated with AN in our combined European sample.

Perspectives: molecular genetic research in human obesity.

Within the past decade the molecular basis of single forms of monogenic obesity has been elucidated. With the exception of functionally relevant mutations in the melanocortin-4 receptor gene, which occur in approximately 2-4% of extremely obese individuals, all other currently known monogenic forms are rare and additionally associated with distinct endocrinological abnormalities. A large number of association studies have been performed in 'normal' obesity. Whereas many associations have been reported, it is largely unclear which of these represent true positive findings. Over 20 genome scans pertaining to obesity and related phenotypes have been performed; specific chromosomal peak regions have been identified in different scans. We review the current status and discuss relevant issues related to phenotyping, association and linkage studies. We recommend that the procedure via which a consensus is reached as to what constitutes a true positive association finding requires formalization.

No evidence for involvement of the promoter polymorphism -866 G/A of the UCP2 gene in childhood-onset obesity in humans.

Recently, an association between obesity and the G-allele of the - 866 G/A polymorphism in the promoter region of uncoupling protein-2 gene (UCP2) was reported. Both allele frequencies and genotype distributions for this polymorphism differed between obese individuals and never-obese controls. We attempted to confirm this finding. Genotyping was performed by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). We analysed transmission disequilibrium of the (wild type) G-allele for 200 extremely obese children and adolescents from 93 concordant sib pair families using the pedigree disequilibrium test. Additionally, using a one-sided asymptotic Pearson's chi 2-test, we tested whether the G-allele occurs more frequently in 277 extremely obese children and adolescents (including the 93 index patients of the concordant sib pairs) than in 188 never-obese controls. The one-sided asymptotic Cochran Armitage trend test was used to determine differences in genotype frequencies between extremely obese and healthy underweight individuals. The PDT analysis revealed no evidence for transmission disequilibrium in obesity. Allele and genotype frequencies did not differ between the extremely obese and never-obese subjects. In conclusion, we cannot confirm the results of ) in our young sample.

5-HT2A promoter polymorphism -1438G/A in children and adolescents with obsessive-compulsive disorders.

Positive association between obsessive compulsive disorder (OCD) and the A-allele of the 5-HT(2A)-receptor promoter polymorphism -1438G/A has recently been reported in adults. We performed an association analysis of this polymorphism in 55 children and adolescents with OCD and in 223 controls consisting of unrelated students. We detected statistically significant differences in genotype (P < 0.05) and allele frequencies (P < 0.05) between individuals with OCD and controls. In this, to our knowledge, first association study based on children and adolescents with OCD, we confirm an association of the A-allele of the 5-HT2A receptor gene with OCD.

Genetic predisposition to obesity in bulimia nervosa: a mutation screen of the melanocortin-4 receptor gene.

Obesity has been identified as a risk factor for the development of bulimia nervosa (BN). Accordingly, we hypothesize that genotypes predisposing to obesity can be detected in patients with this eating disorder. In order to investigate this hypothesis we screened the melanocortin-4 receptor gene (MC4R) for mutations using single strand conformation analysis in 81 female inpatients treated for BN. A single patient with both extreme obesity and BN had a haplo-insufficiency mutation in the MC4R. Comparison of current and maximal body mass index (BMI) of all patients with cross-sectionally obtained BMI in the general population revealed an age appropriate distribution for current BMI and a substantially increased frequency for overweight at time of maximal BMI. Our findings suggest that overweight is a risk factor for BN in clinically ascertained patients. For the first time a genotype predisposing to obesity has been detected in an extremely obese patient with BN.

No evidence for involvement of alleles of the 825-C/T polymorphism of the G-protein subunit beta 3 in body weight regulation.

The 825-C/T polymorphism of the beta 3 subunit of the heterotrimeric G protein gene (GNB3) has been shown to be associated with essential hypertension in humans. Recently, it was also reported that the 825-T allele has a higher frequency in obese than non-obese hypertensives suggesting that the primary effect of this allele is on body weight. The association to hypertension might merely be a secondary effect of the higher weight of the respective allele carriers. To investigate an involvement of the 825-T allele in body weight regulation in young individuals, we evaluated allele frequencies in 440 extremely obese children and adolescents (82.9% had a body mass index [BMI] > or = 99th percentile), 51 obese students (BMI > or = 90th percentile), 110 normal weight students (BMI between 40th and 60th percentile) and 144 underweight students (BMI < or = 15th percentile). The study groups were genotyped by polymerase chain reaction with subsequent restriction fragment length polymorphism analysis (PCR-RFLP). The one-sided Yates-corrected chi(2)-test and the Cochran-Armitage trend test for association were performed. Tests for association were negative. The 825-T allele frequencies were similar in the four study groups belonging to different weight ranges (extreme early onset obesity: 0.29; obesity: 0.28; normal weight: 0.35; underweight: 0.32). Similarly, genotype frequencies did not differ between the groups. We concluded that the 825-T allele of the GNB3 does not play a major role in weight regulation in German children, adolescents and young adults.

Prevalence of obesity in adolescent and young adult patients with and without schizophrenia and in relationship to antipsychotic medication.

The prevalence of obesity in inpatients of a German psychiatric rehabilitation center for adolescents and young adults (mean age 19.5 years) is assessed and set into relationship to diagnosis and medication regimen. In a cross-sectional naturalistic study body weights and heights of 151 inpatients, 109 of whom presented with ICD-10 schizophrenia spectrum disorders, were measured for the calculation of body mass indices (BMI, kg/m2); current medication regimen including the duration of treatment was assessed from medical records. BMIs were plotted into gender- and age-specific BMI-percentiles representative for the German population. Among the whole study population, obesity (BMI > or =90th percentile) was apparent in 44/98 (45%) of the male and in 31/53 (59%) of the female inpatients (overall: 50%). With respect to schizophrenia spectrum disorders, 36/70 (51%) males and 25/39 (64%) females (overall: 56%) were obese in contrast to 14/42 (33%) among the individuals without schizophrenia. Set into relationship to the treatment groups, the prevalence rates of obesity were 64% in patients treated with clozapine (n=69), 56% for other atypical antipsychotics (olanzapine, sulpiride, risperidone; n=27), 30% for classic antipsychotics (haloperidol, flupentixol, perazine; n=20) and 28% for the currently drug-free group (n=25). Together with other published findings in adults, these results suggest an increased prevalence of obesity among young patients with schizophrenia and especially among patients chronically treated with atypical antipsychotics.

N-acetyltransferase 2 phenotype in painters with bladder cancer and controls.

AIM: This study was designed to evaluate the impact of N-acetyltransferase 2 (NAT2, substrate: aromatic amines) in painters with bladder cancer and controls. BACKGROUND: Until the beginning of the 1960s, painters in Germany have used, among others, azo dyes based on carcinogenic aromatic amines. MATERIALS AND METHODS: Sixteen painters with bladder cancer and 26 healthy painters (controls) who were from the same area in Germany and in the same age group (+/-5 years) were recruited into the study. All subjects were phenotyped for NAT2 by the molar ratio of two caffeine metabolites in the urine which was determined by the high performance liquid chromatography (HPLC) method. The number of years working as a painter, age at first exposure to paints and the life-time smoking habits of subjects were noted. RESULTS: Fourteen cases and 23 controls had been exposed to paints before 1960. Age at first exposure to paint was 15.5 years (SD 5.3) in cases and 16.3 (SD 4.9) years in controls. Cases had worked 31.1 years (SD 15.0) and controls had worked 44.8 years (SD 7.2) as painters. Four cases and 7 controls were non-smokers. In this study, 88% of cases and 65% of controls were of the "slow" acetylation and phenotype, CONCLUSION: The result point to and impact of the slow acetylation status as an individual risk factor for bladder cancer in persons occupationally exposed to amounts of carcinogenic aromatic amines released from water-soluble azo dyes.

The genetics of obesity: practical implications.

Over the past years substantial progress has been made in the molecular elucidation of monogenic forms of obesity both in rodents and in humans. In addition, several quantitive trait loci have been mapped in mice. In humans, non-parametric linkage studies have led to the identification of relevant chromosomal regions, some of which have already been confirmed. In this review we focus on an interpretation of the heritability estimates obtained in twin, family and adoption studies. These estimates include both direct and indirect genetic effects. Non-additive genetic factors seemingly contribute even more than additive factors. The importance of the non-shared environment is stressed. Gene x gene interactions need to be considered when interpreting recent molecular genetic results pertaining to haplo-insufficiency mutations in the melanocortin-4 receptor gene. We conclude by discussing the implications of the recent molecular findings in humans for phenotypical assessment in ongoing family studies.