Using admixture analysis to examine birth-cohort effects on age at onset of bipolar disorder

OBJECTIVE

It is suggested that age at onset (AAO) of bipolar I disorder (BP-I) is decreasing. We tested for a birth-cohort effect on AAO using admixture analysis.

METHOD

A clinical sample of 3896 BP-I cases was analysed using two approaches: (i) in a subsample with untruncated AAO × birth year distribution (n = 1865), we compared the best-fitting model for the observed AAO in patients born ≤1960 and >1960, (ii) to control for potential confounders, two separate subsamples born ≤1960 and >1960 were matched for age at interview (n = 250), and a further admixture analysis was undertaken.

RESULTS

The two approaches indicated that the proportion of cases in the early AAO category was significantly greater in cases born >1960; manic onsets were also more frequent in the early onset BP-I cases born >1960.

CONCLUSION

The decrease in AAO of BP-I in recent birth-cohorts appears to be associated with an increase in the proportion of cases in the early onset subgroup; not with a decrease in the mean AAO in each putative subgroup. This could indicate temporal changes in exposure to risk factors for mania.

Cannabis use disorder is associated with greater illness severity in tobacco smoking patients with bipolar disorder

OBJECTIVE

Cannabis use disorders (CUD) may influence the course of bipolar disorder (BD), but key confounding factors such as tobacco smoking have not been adequately addressed. This study examined whether CUD was associated with a more severe illness course in tobacco smoking BD patients.

METHODS

A sample of French and Norwegian tobacco smoking patients with BD I and II (N=642) was investigated. DSM-IV diagnoses and other characteristics were obtained through personal interviews using structured questionnaires. The association between CUD and illness course was assessed in regression analyses.

RESULTS

In bivariate analyses, CUD was associated with earlier BD onset, higher frequency of manic (in BD I) and depressive episodes and hospitalizations per illness year, and a higher occurrence of psychotic episodes. After controlling for potential confounders, the relationships with earlier BD onset (B=-5.60 95% CI=-7.65 to -3.64), and increased rates of manic episodes (OR=1.93, 95% CI: 1.15 to 3.23) and hospitalizations (OR=2.93, 95% CI: 1.85 to 4.64) remained statistically significant.

LIMITATIONS

Despite the multivariate approach, differences between the two samples may lead to spurious findings related to hidden confounders. Substance use and mood episode information was collected retrospectively, and potential birth cohort effects could not be controlled for.

CONCLUSION

Studies have found associations between tobacco smoking and poorer outcomes in BD. In this study on tobacco smoking BD patients we report an association between CUD and illness severity, suggesting that CUD exacerbates the disease evolution independently of tobacco smoking. Specific treatment and prevention programs addressing CUD in BD patients are warranted.

An automated quasi-continuous capillary refill timing device

Capillary refill time (CRT) is a simple means of cardiovascular assessment which is widely used in clinical care. Currently, CRT is measured through manual assessment of the time taken for skin tone to return to normal colour following blanching of the skin surface. There is evidence to suggest that manually assessed CRT is subject to bias from ambient light conditions, a lack of standardisation of both blanching time and manually applied pressure, subjectiveness of return to normal colour, and variability in the manual assessment of time. We present a novel automated system for CRT measurement, incorporating three components: a non-invasive adhesive sensor incorporating a pneumatic actuator, a diffuse multi-wavelength reflectance measurement device, and a temperature sensor; a battery operated datalogger unit containing a self contained pneumatic supply; and PC based data analysis software for the extraction of refill time, patient skin surface temperature, and sensor signal quality.

Through standardisation of the test, it is hoped that some of the shortcomings of manual CRT can be overcome. In addition, an automated system will facilitate easier integration of CRT into electronic record keeping and clinical monitoring or scoring systems, as well as reducing demands on clinicians.

Summary analysis of volunteer (n = 30) automated CRT datasets are presented, from 15 healthy adults and 15 healthy children (aged from 5 to 15 years), as their arms were cooled from ambient temperature to 5°C. A more detailed analysis of two typical datasets is also presented, demonstrating that the response of automated CRT to cooling matches that of previously published studies.

Genetics of emotional reactivity in bipolar disorders

BACKGROUND

Emotional reactivity has been proposed as a relevant intermediate phenotype of bipolar disorder (BD). Our goal was to identify genetic factors underlying emotional reactivity in a sample of bipolar patients.

METHODS

Affect intensity (a proxy measure of emotional reactivity) was measured in a sample of 281 euthymic patients meeting DSM-IV criteria for BD. We use a validated dimensional tool, the 40-item self-report Affect Intensity Measure scale developed by Larsen and Diener. Patients with BD were genotyped for 475. 740 SNPs (using Illumina HumanHap550 Beadchips or HumanHap610 Quad chip). Association was investigated with a general mixed regression model of the continuous trait against genotypes, including gender as covariate.

RESULTS

Four regions (1p31.3, 3q13.11, 11p15.1 and 11q14.4) with a p-value lower or equal to 5×10(-6) were identified. In these regions, the joint effect of the four variants accounted for 24.5% of the variance of AIM score. Epistasis analysis did not detect interaction between these variants. In the 11p15.1 region, the rs10766743 located in the intron of the NELL1 gene remained significant after correction for multiple testing (p=2×10(-7)).

CONCLUSIONS

These findings illustrate that focusing on quantitative intermediate phenotypes can facilitate the identification of genetic susceptibility variants in BD.

Caractéristiques cliniques pour un meilleur choix thérapeutique dans la dépression bipolaire

Face aux difficultés persistantes pour traiter efficacement la dépression bipolaire et à face à la complexité des guidelines, il est indispensable d’identifier des prédicteurs de réponse aux traitements médicamenteux. Les dépressions bipolaires sont plus difficiles à traiter que les dépressions unipolaires en raison d’une moins bonne réponse aux traitements pharmacologiques et du risque de virage de l’humeur. Dans les recommandations internationales, on observe depuis quelques années une évolution qui donne une place plus importante aux thymorégulateurs classiques (lithium et valproate), puis une apparition des antipsychotiques et enfin une régression des antidépresseurs . Rien cependant n’indique dans ces recommandations comment orienter son choix, notamment en fonction de caractéristiques cliniques de la dépression. Des études cliniques avec une approche dimensionnelle ont montré que les dépressions bipolaires pouvaient être caractérisées par la réactivité émotionnelle mesurée par la Multidimensional Assessment of Thymic States Scale (MAThyS) , celle-ci pouvant constituer un marqueur d’intérêt de réponse aux traitements pharmacologiques. Dans cette perspective, l’utilisation de modèles statistiques originaux de trajectoire pour différencier des profils cliniques de réponses aux traitements a permis de montrer que l’hyperréactivité émotionnelle serait un facteur prédictif d’une bonne réponse aux antipsychotiques atypiques. La force de cette étude réalisée sur six semaines consécutives est de pouvoir observer la réponse aux traitements quel que soit l’épisode en cours sur un grand nombre de sujets, et l’une des limites était le faible effectif des patients sous antidépresseurs. Au vu de ces résultats prometteurs, nous prévoyons d’élargir l’échantillon et d‘utiliser la MAthyS pour suivre les réponses thérapeutiques.

Intérêt d’un agoniste dopaminergique dans le traitement des dépressions bipolaires : ce que nous dit la littérature

Le pramipexole est un agoniste dopaminergique, connu pour son utilisation dans la maladie de Parkinson idiopathique, dont la particularité est d’avoir une affinité sélective pour les récepteurs D3 de la voie mésolimbique. Le rôle de la dopamine ayant été mis en évidence dans la physiopathologie de la dépression, des études se sont intéressées à l’action antidépressive du pramipexole et ont démontré une efficacité comparable à celle d’un inhibiteur sélectif de la recapture de la sérotonine dans le traitement des épisodes dépressifs unipolaires . Du fait de la résistance aux traitements conventionnels de certaines formes de dépressions bipolaires, plusieurs études ont testé l’intérêt de thérapeutiques moins conventionnelles, en particulier le pramipexole, dans le traitement des dépressions bipolaires réfractaires . Les données actuelles concernant l’efficacité antidépressive de ce traitement dans les dépressions bipolaires résistantes sont peu nombreuses, et semblent toutefois en faveur de taux de réponse et de rémission significativement plus importants et plus précoces (dès la 3e semaine) en comparaison à des antidépresseurs classiques ou d’un placebo. Nous détaillerons les données de la littérature concernant les dépressions bipolaires. La dose moyenne quotidienne entre les études était d’1,6 mg au profil d’une bonne tolérance , ce qui était confirmé par les études de suivi au long court. Toutefois, le faible nombre d’études réalisées ne fournissait pas d’informations sur le profil clinique des patients qui pourraient bénéficier de ce type de traitement. Du fait de son action agoniste sélective centrale sur une voie impliquée dans les processus motivationnels et de récompense, on peut supposer que certaines dépressions caractérisées par une apathie et une hyporéactivité émotionnelle seraient davantage susceptibles de bien répondre à ce traitement. Afin de confirmer cette hypothèse, nous présenterons une série d’observations cliniques chez des patients souffrant de dépression bipolaire, pour lesquels nous avons évalué l’efficacité du pramipexole sur les symptômes de dépression.

Wnt signalling in gynaecological cancers: A future target for personalised medicine?

The three major gynaecological cancers, ovarian, uterine and cervical, contribute a significant burden to global cancer mortality, and affect women in both developed and developing countries. However, unlike other cancer types that have seen rapid advances and incorporation of targeted treatments in recent years, personalised medicine is not yet a reality in the treatment of gynaecological cancers. Advances in sequencing technology and international collaborations and initiatives such as The Cancer Genome Atlas are now revealing the molecular basis of these cancers, and highlighting key signalling pathways involved. One pathway which plays a role in all three cancer types, is the Wnt signalling pathway. This complex developmental pathway is altered in most human malignancies, and members of this pathway, particularly the recently linked ROR receptor tyrosine kinases may be attractive future therapeutic targets. This review provides an up-to-date summary of research into Wnt signalling and ovarian, uterine and cervical cancers, and discusses the potential of the Wnt pathway as a future target for personalised medicine in gynaecological cancers.

Violent suicidal behaviour in bipolar disorder is associated with nitric oxide synthase 3 gene polymorphism

OBJECTIVE

Given the importance of nitric oxide system in oxidative stress, inflammation, neurotransmission and cerebrovascular tone regulation, we postulated its potential dysfunction in bipolar disorder (BD) and suicide. By simultaneously analysing variants of three isoforms of nitric oxide synthase (NOS) genes, we explored interindividual genetic liability to suicidal behaviour in BD.

METHOD

A total of 536 patients with BD (DSM-IV) and 160 healthy controls were genotyped for functionally relevant NOS1, NOS2 and NOS3 polymorphisms. History of suicidal behaviour and violent suicide attempt was documented for 511 patients with BD. Chi-squared test was used to perform genetic association analyses and logistic regression to test for gene-gene interactions.

RESULTS

NOS3 rs1799983 T homozygous state was associated with violent suicide attempts (26.4% vs. 10.8%, in patients and controls, P = 0.002, corrected P (Pc) = 0.004, OR: 2.96, 95% CI = 1.33-6.34), and this association was restricted to the early-onset BD subgroup (37.9% vs. 10.8%, in early-onset BD and controls, P = 0.0003, Pc = 0.0006 OR: 5.05, 95% CI: 1.95-12.45), while we found no association with BD per se and no gene-gene interactions.

CONCLUSION

Our results bring further evidence for the potential involvement of endothelial NOS gene variants in susceptibility to suicidal behaviour. Future exploration of this pathway on larger cohort of suicidal behaviour is warranted.

Increased risk of suicide attempt in bipolar patients with severe tobacco dependence

BACKGROUND

The aim of our study was to investigate, in bipolar patients, the association between tobacco status (use and dependence) and history of suicide attempt, and to assess the possible role of inflammation as a missing link in the association between smoking status and history of suicide attempt.

METHODS

A total of 453 adult bipolar out-patients recruited in the French FondaMental Advanced Centres of Expertise for Bipolar Disorder were divided into two subgroups: 274 patients without past history of suicide attempt (non-SA), and 179 patients with a past history of suicide attempt (SA). Tobacco use and dependence, psychiatric and somatic comorbidities, history of childhood abuse, family history of suicide were assessed. Fasting blood tests yielded samples collected for the measurement of high sensitivity (hs-)CRP.

RESULTS

The risk of suicide attempt increased with smoking dependence. Notably, bipolar patients with a history of suicide attempt were three times more likely to have severe tobacco dependence, independently of confounding factors. However, we failed to find arguments promoting the hypothesis of inflammatory markers (through hs-CRP measure) in the link between tobacco dependence and suicidal behavior.

CONCLUSIONS

We found a significant association between severe tobacco dependence and history of suicide attempt, but not with level of CRP, independently of confusing factors. Longitudinal studies taken into account all these potential confusing factors are needed to confirm our results.

Clinical and neuropsychological characteristics of euthymic bipolar patients having a history of severe suicide attempt

OBJECTIVE

Identifying bipolar patients at high-suicide risk is a major health issue. To improve their identification, we compared dimensional and neuropsychological profile of bipolar patients with or without history of suicide attempt, taking into account suicidal severity (i.e. admission to intensive ward).

METHOD

A total of 343 adult euthymic bipolar out-patients recruited in the French FondaMental Advanced Centres of Expertise for Bipolar Disorder were divided into three subgroups: 214 patients without history of suicide attempt, 88 patients with past history of non-severe suicide attempt and 41 patients with past history of severe suicide attempt. General intellectual functioning, speed of information processing, verbal learning and memory, verbal fluency and executive functioning were assessed.

RESULTS

Severe suicide attempters had lower affective intensity and lability than non-severe attempters. Severe suicide attempters outperformed non-severe attempters for verbal learning and non-attempters for Stroop word reading part after adjustment for study centre, age, gender, educational level, antipsychotics use, depression score, anxious and addictive comorbidities.

CONCLUSION

Neuropsychological tasks commonly used to assess bipolar patients do not seem accurate to identify suicide attempters in euthymic patients. In the future, decision-making and emotional recognition tasks should be assessed. Moreover, clinical and neuropsychological profiles should be considered together to better define suicidal risk.

Sleep in patients with remitted bipolar disorders: a meta-analysis of actigraphy studies

OBJECTIVE

Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls.

METHOD

A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI).

RESULTS

Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07).

CONCLUSION

This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms.

Le trouble bipolaire et ses biomarqueurs : quoi de neuf ?

Le trouble bipolaire (TB) est une maladie chronique sévère qui atteint 1 à 4 % de la population générale. Le TB entraîne un handicap majeur lié au très haut niveau de rechute (60 % à 2 ans), à l’impact fonctionnel des comorbidités associées et aux troubles persistants entre les épisodes. Cette maladie récurrente a été reconnue par l’Organisation mondiale de la santé (OMS) comme la septième cause de handicap par année de vie parmi toutes les maladies dans la population des 15 à 44 ans [1]. L’arrivée nouvelle du DSM-5 témoigne de la volonté d’amélioration des outils de classification diagnostique à partir des biomarqueurs validés dans chaque trouble psychiatrique. Néanmoins, l’identification de tels biomarqueurs n’est pas toujours facile et se heurte à la complexité et à l’hétérogénéité des pathologies dont celle du trouble bipolaire. Ainsi, des efforts croissants sont fait afin d’identifier de nouveaux biomarqueurs du TB qui corrèlent avec des symptômes ou des dimensions cliniques de la maladie. Des travaux récents ont mis l’accent sur l’intérêt de biomarqueurs pour les TB dans le champ de la neuro-imagerie [2], des rythmes circadiens [3] et de certains marqueurs moléculaires [4]. Ces biomarqueurs ont pour objectif d’aider non seulement au meilleur dépistage du trouble et à sa meilleure compréhension physiopathologique, mais aussi à la prévention des rechutes, à l’évaluation de l4efficacité des thérapeutiques et à la prédiction de la réponse thérapeutique. Cette recherche de biomarqueurs s’inscrit dans un effort général de la recherche d’une médecine personnalisée.

Randomised clinical trial: Polyethylene glycol 3350 with sports drink vs. polyethylene glycol with electrolyte solution as purgatives for colonoscopy--the incidence of hyponatraemia

BACKGROUND

Polyethylene glycol 3350 plus sports drink (PEG-SD) is a hypo-osmotic purgative commonly used for colonoscopy, though little safety data are available.

AIM

To evaluate the effect of PEG-SD on serum sodium (Na) and other electrolytes compared with PEG-electrolyte solution (PEG-ELS).

METHODS

We performed a single center, prospective, randomised, investigator-blind comparison of PEG-ELS to PEG-SD in out-patients undergoing colonoscopy. Laboratories were obtained at baseline and immediately before and after colonoscopy. The primary endpoint was development of hyponatraemia (Na <135 mmol/L) the day of colonoscopy. Changes in electrolyte levels were computed as the difference between the lowest value on the day of colonoscopy and baseline. Purgative tolerance and efficacy were assessed.

RESULTS

A total of 389 patients were randomised; 364 took purgative and had baseline and day of colonoscopy labs (180 PEG-SD, 184 PEG-ELS). The groups were well matched except for a higher fraction of women and Blacks in PEG-ELS. Seven patients (3.9%) in PEG-SD and four patients (2.2%) in PEG-ELS developed hyponatraemia (OR = 1.82, 95% CI: 0.45-8.62, P = 0.376). Changes in electrolytes from baseline were small but significantly worse with PEG-SD for sodium, potassium and chloride (P = 0.001, 0.012, 0.001, respectively). Preparation completion, adverse events, and overall colon cleansing were similar between the groups, but PEG-ELS had more excellent preparations (52% vs. 30%; P = 0.001).

CONCLUSIONS

Greater, but very modest, electrolyte changes occur with PEG-SD. Hyponatraemia is infrequent with both purgatives. A significant increase in hyponatraemia was not identified for PEG-SD vs. PEG-ELS, but the sample size may have been inadequate to identify a small, but clinically important difference. ClinicalTrials.gov identifier NCT01299779.

Links between sleep and body mass index in bipolar disorders: an exploratory study

STUDY OBJECTIVES

Obesity and excess bodyweight are highly prevalent in individuals with bipolar disorders (BD) and are associated with adverse consequences. Multiple factors may explain increased bodyweight in BD including side effects of psychotropic medications, and reduced physical activity. Research in the general population demonstrates that sleep disturbances may also contribute to metabolic burden. We present a cross-sectional study of the associations between body mass index (BMI) and sleep parameters in patients with BD as compared with healthy controls (HC).

METHODS

Twenty-six French outpatients with remitted BD and 29 HC with a similar BMI completed a 21-day study of sleep parameters using objective (actigraphy) and subjective (PSQI: Pittsburgh Sleep Quality Index) assessments.

RESULTS

In BD cases, but not in HC, higher BMI was significantly correlated with lower sleep efficiency (P=0.009) and with several other sleep parameters: shorter total sleep time (P=0.01), longer sleep onset latency (P=0.05), higher fragmentation index (P=0.008), higher inter-day variability (P=0.05) and higher PSQI total score (P=0.004).

CONCLUSIONS

The findings suggest a link between a high BMI and several sleep disturbances in BD, including lower sleep efficiency. Physiological mechanisms in BD cases may include an exaggeration of phenomena observed in non-clinical populations. However, larger scale studies are required to clarify the links between metabolic and sleep-wake cycle disturbances in BD.

Additive effects of childhood abuse and cannabis abuse on clinical expressions of bipolar disorders

BACKGROUND

Previous studies of bipolar disorders indicate that childhood abuse and substance abuse are associated with the disorder. Whether both influence the clinical picture, or if one is mediating the association of the other, has not previously been investigated.

METHOD

A total of 587 patients with bipolar disorders were recruited from Norway and France. A history of childhood abuse was obtained using the Childhood Trauma Questionnaire. Diagnosis and clinical variables, including substance abuse, were based on structured clinical interviews (Structured Clinical Interview for DSM-IV Axis I disorders or French version of the Diagnostic Interview for Genetic Studies).

RESULTS

Cannabis abuse was significantly associated with childhood abuse, specifically emotional and sexual abuse (χ 2 = 8.63, p = 0.003 and χ 2 = 7.55, p = 0.006, respectively). Cannabis abuse was significantly associated with earlier onset of the illness (z = -4.17, p < 0.001), lifetime history of at least one suicide attempt (χ 2 = 11.16, p = 0.001) and a trend for rapid cycling (χ 2 = 3.45, p = 0.06). Alcohol dependence was associated with suicide attempt (χ 2 = 10.28, p = 0.001), but not with age at onset or rapid cycling. After correcting for possible confounders and multiple testing, a trend was observed for an interaction between cannabis abuse and childhood abuse and suicide attempt (logistic regression: r 2 = 0.06, p = 0.039). Significant additive effects were also observed between cannabis abuse and childhood abuse on earlier age at onset (p < 0.001), increased rapid cycling and suicide attempt (logistic regression: r 2 = 0.03-0.04, p < 0.001). No mediation effects were observed; childhood abuse and cannabis abuse were independently associated with the disorder.

CONCLUSIONS

Our study is the first to demonstrate significant additive effects, but no mediation effects, between childhood abuse and cannabis abuse on increased clinical expressions of bipolar disorders.

Overexpression of the polarity protein PAR-3 in clear cell renal cell carcinoma is associated with poor prognosis

The partition-defective 3 (PAR-3) protein is implicated in the development and maintenance of cell polarity and is associated with proteins that mediate the changes in cytoskeleton organization required for cell polarity establishment. In this work, we used two original primary cell lines (R-180 and R-305) derived from clear cell Renal Cell Carcinoma (ccRCC) surgical specimens of a patient with unfavorable clinical course (R-180 cells) and a patient with favorable prognosis (R-305 cells) to identify genetic and molecular features that may explain the survival difference of the two patients. The cytogenetic analysis of these cell lines revealed that the PARD3 gene was amplified only in the R-180 cell line that was derived from an aggressive ccRCC. PARD3 gene amplification was associated with overexpression of the encoded protein and altered cytoskeleton organization. Consistently, PARD3 knockdown in R-180 cells restored the cytoskeleton organization and reduced cell migration in comparison to non-transfected cells. Immunohistochemical analysis of ccRCC samples from a cohort of 96 patients with a follow-up of 6 years revealed that PAR-3 overexpression was correlated with poor survival. Our results suggest that PAR-3 has a role in the clinical aggressiveness of ccRCC, possibly by promoting cell migration.

Allelic differences between Europeans and Chinese for CREB1 SNPs and their implications in gene expression regulation, hippocampal structure and function, and bipolar disorder susceptibility

Bipolar disorder (BD) is a polygenic disorder that shares substantial genetic risk factors with major depressive disorder (MDD). Genetic analyses have reported numerous BD susceptibility genes, while some variants, such as single-nucleotide polymorphisms (SNPs) in CACNA1C have been successfully replicated, many others have not and subsequently their effects on the intermediate phenotypes cannot be verified. Here, we studied the MDD-related gene CREB1 in a set of independent BD sample groups of European ancestry (a total of 64,888 subjects) and identified multiple SNPs significantly associated with BD (the most significant being SNP rs6785[A], P=6.32 × 10(-5), odds ratio (OR)=1.090). Risk SNPs were then subjected to further analyses in healthy Europeans for intermediate phenotypes of BD, including hippocampal volume, hippocampal function and cognitive performance. Our results showed that the risk SNPs were significantly associated with hippocampal volume and hippocampal function, with the risk alleles showing a decreased hippocampal volume and diminished activation of the left hippocampus, adding further evidence for their involvement in BD susceptibility. We also found the risk SNPs were strongly associated with CREB1 expression in lymphoblastoid cells (P<0.005) and the prefrontal cortex (P<1.0 × 10(-6)). Remarkably, population genetic analysis indicated that CREB1 displayed striking differences in allele frequencies between continental populations, and the risk alleles were completely absent in East Asian populations. We demonstrated that the regional prevalence of the CREB1 risk alleles in Europeans is likely caused by genetic hitchhiking due to natural selection acting on a nearby gene. Our results suggest that differential population histories due to natural selection on regional populations may lead to genetic heterogeneity of susceptibility to complex diseases, such as BD, and explain inconsistencies in detecting the genetic markers of these diseases among different ethnic populations.

[Cytogenetics profiles of renal carcinoma]

Renal carcinomas are histologically and prognostically heterogeneous. Genomic as well as chromosomal studies of these tumors have permitted a better comprehension of molecular mechanisms implicated in their development and progression. The most frequent histological subtypes are characterized by recurrent cytogenetic abnormalities, such as the loss of the chromosome 3 short arm involving a VHL gene copy in clear cell renal carcinomas, or trisomies 7 and 17 in papillary renal cell carcinomas. New histological subtypes like renal carcinomas associated with Xp11.2 translocations have also been individualized. Besides diagnosis, some chromosomal aberrations like the loss of a short arm of chromosome 9 in different renal carcinoma histological subtypes have a worse prognostic impact. The identification of chromosomal shuffles contributes in backing histological diagnosis and in precising the individual prognosis of patients. This review describes chromosomal abnormalities associated to renal carcinomas and their impact for an accurate classification of these tumors and the evaluation of their prognosis.