Cytochrome P450 genotypes are not associated with refractoriness to antipsychotic treatment

Evidence validating the influence of the cytochrome P450 (CYP) 2D6 and 2C19 enzymes genetic polymorphisms in the response to antipsychotics is scarce. We examined the hypothesis that a higher prevalence of CYP2D6 and/or CYP2C19 ultra rapid metabolizers might be found among refractory schizophrenia patients. Three groups were studied: refractory and non-refractory schizophrenia patients, and healthy controls. Participants were genotyped for CYP2D6 and CYP2C19 polymorphisms and classified in metabolic phenotypes. No between-group differences in the distribution of the phenotypes were found. Therefore, our findings do not support the CYPs 2D6 and 2C19 genotyping in the prediction of therapeutic response in schizophrenia.

Large-scale Transcriptome Analyses Reveal New Genetic Marker Candidates of Head, Neck, and Thyroid Cancer

A detailed genome mapping analysis of 213,636 expressed sequence tags (EST) derived from nontumor and tumor tissues of the oral cavity, larynx, pharynx, and thyroid was done. Transcripts matching known human genes were identified; potential new splice variants were flagged and subjected to manual curation, pointing to 788 putatively new alternative splicing isoforms, the majority (75%) being insertion events. A subset of 34 new splicing isoforms (5% of 788 events) was selected and 23 (68%) were confirmed by reverse transcription-PCR and DNA sequencing. Putative new genes were revealed, including six transcripts mapped to well-studied chromosomes such as 22, as well as transcripts that mapped to 253 intergenic regions. In addition, 2,251 noncoding intronic RNAs, eventually involved in transcriptional regulation, were found. A set of 250 candidate markers for loss of heterozygosis or gene amplification was selected by identifying transcripts that mapped to genomic regions previously known to be frequently amplified or deleted in head, neck, and thyroid tumors. Three of these markers were evaluated by quantitative reverse transcription-PCR in an independent set of individual samples. Along with detailed clinical data about tumor origin, the information reported here is now publicly available on a dedicated Web site as a resource for further biological investigation. This first in silico reconstruction of the head, neck, and thyroid transcriptomes points to a wealth of new candidate markers that can be used for future studies on the molecular basis of these tumors. Similar analysis is warranted for a number of other tumors for which large EST data sets are available.

Transcriptome analysis of the acoelomate human parasite Schistosoma mansoni

Schistosoma mansoni is the primary causative agent of schistosomiasis, which affects 200 million individuals in 74 countries. We generated 163,000 expressed-sequence tags (ESTs) from normalized cDNA libraries from six selected developmental stages of the parasite, resulting in 31,000 assembled sequences and 92% sampling of an estimated 14,000 gene complement. By analyzing automated Gene Ontology assignments, we provide a detailed view of important S. mansoni biological systems, including characterization of metazoa-specific and eukarya-conserved genes. Phylogenetic analysis suggests an early divergence from other metazoa. The data set provides insights into the molecular mechanisms of tissue organization, development, signaling, sexual dimorphism, host interactions and immune evasion and identifies novel proteins to be investigated as vaccine candidates and potential drug targets.

Association of a new polymorphism in ALOX12 gene with bipolar disorder

Bipolar disorder (BPD) is characterised by episodes of excitement interspersed with periods of depression. The role of genetic factors in BPD is indicated by studies in monozygotic twins showing 40-70 % of concordance. Studies using genetic markers showed linkage of genes for affective disorders in different chromosome regions, emphasising the polygenic and multifactorial traits. The main goal of our research is to search non-synonymous SNPs (those that result in modifications in protein sequence) in genes that can be associated with psychiatric diseases as suggested by genomic mapping and/or by physiological function of the protein. Using DNA sequencing we could confirm a new non-synonymous SNP in the conservative domain of the ALOX12 gene (17p13.1), suggested by EST alignment. This SNP is an alteration from G to A that leads to a change of an arginine (A) to a glutamine in one of the most important domains of the protein. This SNP was evaluated by DNA sequencing in 182 patients with BPD and 160 control individuals. An increased presence of allele A among patients (60 % in controls and 73.1 % in cases; chi(2) = 6.581, P = 0.010; OR = 1.8095, 95 % CI = 1.1477-2.853) was found, suggesting an association of this polymorphism with the BPD in this Brazilian sample.