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Background Large sample sizes are often required to detect statistically significant associations between pharmacogenetic markers and treatment response. Meta-analysis may be performed to synthesize data from several studies, increasing sample size and, consequently, power to detect significant genetic effects. However, performing robust synthesis of data from pharmacogenetic studies is often challenging because of poor reporting of key data in study reports. There is currently no guideline for the reporting of pharmacogenetic studies that has been developed using a widely accepted robust methodology. The objective of this project was to develop the STrengthening the Reporting Of Pharmacogenetic Studies (STROPS) guideline. Methods and findings We established a preliminary checklist of reporting items to be considered for inclusion in the guideline. We invited representatives of key stakeholder groups to participate in a 2-round Delphi survey. A total of 52 individuals participated in both rounds of the survey, scoring items with regards to their importance for inclusion in the STROPS guideline. We then held a consensus meeting, at which 8 individuals considered the results of the Delphi survey and voted on whether each item ought to be included in the final guideline. The STROPS guideline consists of 54 items and is accompanied by an explanation and elaboration document. The guideline contains items that are particularly important in the field of pharmacogenetics, such as the drug regimen of interest and whether adherence to treatment was accounted for in the conducted analyses. The guideline also requires that outcomes be clearly defined and justified, because in pharmacogenetic studies, there may be a greater number of possible outcomes than in other types of study (for example, disease–gene association studies). A limitation of this project is that our consensus meeting involved a small number of individuals, the majority of whom are based in the United Kingdom. Conclusions Our aim is for the STROPS guideline to improve the transparency of reporting of pharmacogenetic studies and also to facilitate the conduct of high-quality systematic reviews and meta-analyses. We encourage authors to adhere to the STROPS guideline when publishing pharmacogenetic studies., Marty Chaplin and co-authors recount the development of a guideline for reporting pharmacogenetic studies.

There is strong biological evidence relating alterations in the serotonergic system with mental disorders. These alterations may be originated at the DNA level by sequence mutations that alter the functioning of serotonin receptors and transporter. To test this hypothesis we investigated three genetic variants of the 5-HT2A receptor (-1438G/A, 102T/C and His452Tyr) and two variants of the serotonin transporter (a VNTR in the second intron and a 44 bp insertion/delition in the promoter region of the gene) in a clinical sample recruited in a human isolate and in surrounding areas in Northern Spain (N = 257) and in ethnically matched controls (N = 334). No clear association was found between 5-HT2A variants and psychosis. However, marginal associations were observed between the 5-HTT LPR and VNTR variants and psychosis (Por = 0.05) indicating a minor contribution to psychosis of genetic alterations in this gene.

This study aimed to investigate associations between the response to olanzapine and genetic variations (polymorphisms) in serotonergic transmission related genes in a sample of prospectively studied schizophrenic patients treated with this drug.A total of 51 non-related patients with a DSM-IV diagnosis of schizophrenia were treated with olanzapine (mean dose: 12 mg/day; range: 5-25 mg) and followed-up for at least three months. Response to olanzapine was measured by the difference between baseline and post-treatment scores on the PANSS and GAS scales. The following polymorphisms were studied: serotonin receptor 5-HT2A (102-T/C, His452Tyr), serotonin receptor 5-HT2C (Cys23Ser, -330-GGT/-244-CT), and serotonin transporter (VNTR, 5-HTTLPR).Global clinical improvement, measured with both the GAS and PANSS total scores, was observed. When patients were divided into responders and non-responders, the distribution of genotypic and allelic frequencies was similar to the one observed in previous studies with clozapine. When regression analyses were undertaken, polymorphism 330-GT/-244-CT of the 5-HT2C serotonin receptor and 5-HTTLPR of the serotonin transporter showed a tendency towards the association to olanzapine response.The present study provides preliminary evidence of the important role of variations in serotonin transmission related genes in determining clinical response to olanzapine. Considering previous studies, it can also be concluded that olanzapine and clozapine may have similar affinities to serotonin receptors.

Some patients with idiopathic Parkinson's disease experience hallucinations as a result of treatment with levodopa and dopamine agonists. There is evidence for some heterogeneity in these hallucinating patients based on duration of Parkinson's disease at onset of hallucinations. We compared the frequency of polymorphisms in the dopamine D2 and D3 receptor genes between patients with drug-induced hallucinations and non-hallucinating patients. Two polymorphisms close to DRD2 and one in DRD3 were studied. No association was found with the whole group of hallucinating patients and their controls. However, an association was found with late-onset hallucinations and the C allele of the TaqIA polymorphism, 10.5 kb 3' to DRD2. This polymorphism may be in linkage disequilibrium with a mutation in DRD2 or a nearby gene that predisposes to drug-induced hallucinations which occur later in the course of idiopathic Parkinson's disease.

The Study of Talavera de la Reina analyzes the presence of several cardiovascular risk factors (CVRF) in this city, by means of a cross-sectional study of the population within 1989 and 1990. In this paper, the results on tobacco consumption, as well as the correlation between tobacco consumption and several anthropometric and biochemical parameters, some of which are independent CVRF theirselves, are presented. Seven hundred and two people were evaluated, 332 men and 370 women, with ages between 20 and 79 years, and were randomized according to the current population census. We have carried out a survey to assess smoking habits; physical examination to measure weight and height, systolic and diastolic arterial pressure, blood analysis including total cholesterol, C-HDL, triglycerides and glucose. C-LDL was obtained using the Friedewald-Fredickson formula. Smoking habits among the younger female population is almost equal to male population. Compared by age groups and similar sex, no significant differences were observed related to anthropometric and biochemical parameters between smokers and non-smokers. The lipidic profile of non-smokers against moderate/heavy smokers (smoking 10 or more gr/day) was compared. The presence of an atherogenic profile in 30 to 39-year-old men and in 40 to 49-year-old women was verified, as well as the lower C-HDL levels among younger smokers of both sexes. This provides tobacco with an added value, as it increases the impact of other CVRF in key ages for the pathogenicity of arteriosclerosis.