The added value of daily diary data in 1- and 3-year prediction of psychopathology and psychotic experiences in individuals at risk for psychosis.

This study aimed to assess whether adding information on psychological experiences derived from a daily diary to baseline cross-sectional data could improve short- (1-year) and long-term (3-years) prediction of psychopathology and positive psychotic experiences (PEs). We used 90-day daily diary data from 96 individuals in early subclinical risk stages for psychosis. Stepwise linear regression models were built for psychopathology and PEs at 1- and 3-years follow-up, adding: (1) baseline questionnaires, (2) the mean and variance of daily psychological experiences, and (3) individual symptom network density. We assessed whether similar results could be achieved with a subset of the data (7-14- and 30-days). The mean and variance of the diary improved model prediction of short- and long-term psychopathology and PEs, compared to prediction based on baseline questionnaires solely. Similar results were achieved with 7-14- and 30-day subsets. Symptom network density did not improve model prediction except for short-term prediction of PEs. Simple metrics, i.e., the mean and variance from 7 to 14 days of daily psychological experiences assessments, can improve short- and long-term prediction of both psychopathology and PEs in individuals in early subclinical stages for psychosis. Diary data could be a valuable addition to clinical risk prediction models for psychopathology development.

The dynamic relationship between sleep and psychotic experiences across the early stages of the psychosis continuum.

BACKGROUND: Psychotic disorders develop gradually along a continuum of severity. Understanding factors associated with psychosis development, such as sleep, could aid in identification of individuals at elevated risk. This study aimed to assess (1) the dynamic relationship between psychotic experiences (PEs) and sleep quality and quantity, and (2) whether this relationship differed between different clinical stages along the psychosis continuum. METHODS: We used daily diary data (90 days) of individuals (N = 96) at early stages (i.e. before a first diagnosis of psychosis) along the psychosis continuum. Multilevel models were constructed with sleep quality and sleep quantity as predictors of PEs and vice versa. Post-hoc, we constructed a multilevel model with both sleep quality and quantity as predictors of PEs. In addition, we tested whether associations differed between clinical stages. RESULTS: Within persons, poorer sleep predicted next day PEs (B = -0.02, p = 0.01), but not vice versa. Between persons, shorter sleep over the 90-day period predicted more PEs (B = -0.04, p = 0.002). Experiencing more PEs over 90-days predicted poorer (B = -0.02, p = 0.02) and shorter (B = -1.06, p = 0.008) sleep. We did not find any significant moderation effects for clinical stage. CONCLUSIONS: We found a bidirectional relationship between sleep and PEs with daily fluctuations in sleep predicting next day PEs and general patterns of more PEs predicting poorer and shorter sleep. Our results highlight the importance of assessing sleep as a risk marker in the early clinical stages for psychosis.

Personal Recovery in People With a Psychotic Disorder: A Systematic Review and Meta-Analysis of Associated Factors.

Background: Personal recovery (PR) is a subjective, multidimensional concept, and quantitative research using PR as an outcome is rapidly increasing. This systematic review is intended to support the design of interventions that contribute to PR in psychotic disorders, by providing an overview of associated factors and their weighted importance to PR: clinical factors, social factors, and socio-demographic characteristics are included, and factors related to the concept of PR (organized into CHIME dimensions). Methods: A systematic literature search was conducted from inception to March 2020. Quantitative studies that had used a validated questionnaire assessing the concept of PR were included. Mean effect sizes for the relationship between PR-scale total scores and related factors were calculated using meta-analyses. Sources of heterogeneity were examined using meta-regression tests. Results: Forty-six studies, that used (a total of) eight PR measures, showed that in clinical factors, affective symptoms had a medium negative association with PR-scale total scores (r = -0.44, 95%CI -0.50 to -0.37), while positive, negative and general symptoms had small negative correlations. No association was found with neuro-cognition. Social factors (support, work and housing, and functioning) showed small positive correlations. Gender and age differences had barely been researched. Large associations were found for PR-scale total scores with the CHIME dimensions hope (r = 0.56, 95%CI 0.48-0.63), meaning in life (r = 0.48, 95%CI 0.38-0.58) and empowerment (r = 0.53, 95%CI 0.42-0.63); while medium associations were found with connectedness (r = 0.34, 95%CI 0.43-0.65) and identity (r = 0.43, 95%CI 0.35-0.50). Levels of heterogeneity were high, sources included: the variety of PR measures, variations in sample characteristics, publication bias, variations in outcome measures, and cultural differences. Discussion: Most interventions in mental healthcare aim to reduce symptoms and improve functioning. With regard to stimulating PR, these interventions may benefit from also focusing on enhancing hope, empowerment, and meaning in life. The strength of these findings is limited by the challenges of comparing separate CHIME dimensions with questionnaires assessing the concept of PR, and by the high levels of heterogeneity observed. Future research should focus on the interaction between elements of PR and clinical and social factors over time.

Effectiveness of trauma-focused treatment for patients with psychosis with and without the dissociative subtype of post-traumatic stress disorder.

This study presents secondary analyses of a recently published trial in which post-traumatic stress disorder (PTSD) patients with psychosis (n = 108) underwent 8 sessions of trauma-focused treatment, either prolonged exposure (PE) or eye movement desensitisation and reprocessing (EMDR) therapy. 24.1% fulfilled the criteria for the dissociative subtype, a newly introduced PTSD subtype in DSM-5. Treatment outcome was compared for patients with and without the dissociative subtype of PTSD. Patients with the dissociative subtype of PTSD showed large reductions in clinician-administered PTSD scale (CAPS) score, comparable with patients without the dissociative subtype of PTSD. It is concluded that even in a population with severe mental illness, patients with the dissociative subtype of PTSD do benefit from trauma-focused treatments without a pre-phase of emotion regulation skill training and should not be excluded from these treatments.

Prolonged exposure and EMDR for PTSD v. a PTSD waiting-list condition: effects on symptoms of psychosis, depression and social functioning in patients with chronic psychotic disorders.

BACKGROUND: In patients with psychotic disorders, the effects of psychological post-traumatic stress disorder (PTSD) treatment on symptoms of psychosis, depression and social functioning are largely unknown METHOD: In a single-blind randomized controlled trial (RCT) 155 outpatients in treatment for psychosis (61.3% schizophrenic disorder, 29% schizoaffective disorder) were randomized to eight sessions prolonged exposure (PE; n = 53) or eye movement desensitization and reprocessing (EMDR) (n = 55), or a waiting-list condition (WL, n = 47) for treatment of their co-morbid PTSD. Measures were performed on (1) psychosis: severity of delusions (PSYRATS-DRS), paranoid thoughts (GPTS), auditory verbal hallucinations (PSYRATS-AHRS), and remission from psychotic disorder (SCI-SR-PANSS); (2) depression (BDI-II); (3) social functioning (PSP). Outcomes were compared at baseline, post-treatment, 6-month follow-up and over all data points. RESULTS: Both PE and EMDR were significantly associated with less severe paranoid thoughts post-treatment and at 6-month follow-up, and with more patients remitting from schizophrenia, at post-treatment (PE and EMDR) and over time (PE). Moreover, PE was significantly associated with a greater reduction of depression at post-treatment and at 6-month follow-up. Auditory verbal hallucinations and social functioning remained unchanged. CONCLUSIONS: In patients with chronic psychotic disorders PE and EMDR not only reduced PTSD symptoms, but also paranoid thoughts. Importantly, in PE and EMDR more patients accomplished the status of their psychotic disorder in remission. Clinically, these effects are highly relevant and provide empirical support to the notion that delivering PTSD treatment to patients with psychotic disorders and PTSD deserves increasing recognition and acceptance among clinicians.

Self-esteem treatment in anxiety: A randomized controlled crossover trial of Eye Movement Desensitization and Reprocessing (EMDR) versus Competitive Memory Training (COMET) in patients with anxiety disorders.

BACKGROUND AND PURPOSE: Little is known about treating low self-esteem in anxiety disorders. This study evaluated two treatments targeting different mechanisms: (1) Eye Movement Desensitization and Reprocessing (EMDR), which aims to desensitize negative memory representations that are proposed to maintain low self-esteem; and (2) Competitive Memory Training (COMET), which aims to activate positive representations for enhancing self-esteem. METHODS: A Randomized Controlled Trial (RCT) was used with a crossover design. Group 1 received six sessions EMDR first and then six sessions COMET; group 2 vice versa. Assessments were made at baseline (T0), end of first treatment (T1), and end of second treatment (T2). Main outcome was self-esteem. We included 47 patients and performed Linear Mixed Models. RESULTS: COMET showed more improvements in self-esteem than EMDR: effect-sizes 1.25 versus 0.46 post-treatment. Unexpectedly, when EMDR was given first, subsequent effects of COMET were significantly reduced in comparison to COMET as the first intervention. For EMDR, sequence made no difference. Reductions in anxiety and depression were mediated by better self-esteem. CONCLUSIONS: COMET was associated with significantly greater improvements in self-esteem than EMDR in patients with anxiety disorders. EMDR treatment reduced the effectiveness of subsequent COMET. Improved self-esteem mediated reductions in anxiety and depression symptoms.

Development of a stage-dependent prognostic model to predict psychosis in ultra-high-risk patients seeking treatment for co-morbid psychiatric disorders.

BACKGROUND: Current ultra-high-risk (UHR) criteria appear insufficient to predict imminent onset of first-episode psychosis, as a meta-analysis showed that about 20% of patients have a psychotic outcome after 2 years. Therefore, we aimed to develop a stage-dependent predictive model in UHR individuals who were seeking help for co-morbid disorders. METHOD: Baseline data on symptomatology, and environmental and psychological factors of 185 UHR patients (aged 14-35 years) participating in the Dutch Early Detection and Intervention Evaluation study were analysed with Cox proportional hazard analyses. RESULTS: At 18 months, the overall transition rate was 17.3%. The final predictor model included five variables: observed blunted affect [hazard ratio (HR) 3.39, 95% confidence interval (CI) 1.56-7.35, p < 0.001], subjective complaints of impaired motor function (HR 5.88, 95% CI 1.21-6.10, p = 0.02), beliefs about social marginalization (HR 2.76, 95% CI 1.14-6.72, p = 0.03), decline in social functioning (HR 1.10, 95% CI 1.01-1.17, p = 0.03), and distress associated with suspiciousness (HR 1.02, 95% CI 1.00-1.03, p = 0.01). The positive predictive value of the model was 80.0%. The resulting prognostic index stratified the general risk into three risk classes with significantly different survival curves. In the highest risk class, transition to psychosis emerged on average ⩾8 months earlier than in the lowest risk class. CONCLUSIONS: Predicting a first-episode psychosis in help-seeking UHR patients was improved using a stage-dependent prognostic model including negative psychotic symptoms (observed flattened affect, subjective impaired motor functioning), impaired social functioning and distress associated with suspiciousness. Treatment intensity may be stratified and personalized using the risk stratification.

Cannabis use and transition to psychosis in individuals at ultra-high risk: review and meta-analysis.

BACKGROUND: Previous research has established the relationship between cannabis use and psychotic disorders. Whether cannabis use is related to transition to psychosis in patients at ultra-high risk (UHR) for psychosis remains unclear. The present study aimed to review the existing evidence on the association between cannabis use and transition to psychosis in UHR samples. METHOD: A search of PsychInfo, Embase and Medline was conducted from 1996 to August 2015. The search yielded 5559 potentially relevant articles that were selected on title and abstract. Subsequently 36 articles were screened on full text for eligibility. Two random-effects meta-analyses were performed. First, we compared transition rates to psychosis of UHR individuals with lifetime cannabis use with non-cannabis-using UHR individuals. Second, we compared transition rates of UHR individuals with a current DSM-IV cannabis abuse or dependence diagnosis with lifetime users and non-using UHR individuals. RESULTS: We found seven prospective studies reporting on lifetime cannabis use in UHR subjects (n = 1171). Of these studies, five also examined current cannabis abuse or dependence. Lifetime cannabis use was not significantly associated with transition to psychosis [odds ratio (OR) 1.14, 95% confidence interval (CI) 0.856-1.524, p = 0.37]. A second meta-analysis yielded an OR of 1.75 (95% CI 1.135-2.710, p = 0.01), indicating a significant association between current cannabis abuse or dependence and transition to psychosis. CONCLUSIONS: Our results show that cannabis use was only predictive of transition to psychosis in those who met criteria for cannabis abuse or dependence, tentatively suggesting a dose-response relationship between current cannabis use and transition to psychosis.

[Imagery in psychosis: EMDR as a new intervention in the treatment of delusions and auditory hallucinations]. / Mentale beelden bij psychose: EMDR als een nieuwe interventie bij het behandelen van stemmen en wanen.

BACKGROUND: Historically, psychotherapy has focused on the treatment of patients' verbal representations (thoughts) and has proved particularly successful in the cognitive behavioural treatment of psychosis. However, there is mounting evidence that visual representations (imagery) play an important role in the onset and maintenance of psychiatric disorders, including psychotic symptoms. There are indications that heightened emotionality and vividness of visual representations are associated with severity of psychotic experiences. This may imply that a reduction in the vividness and emotionality of the psychosis-related imagery can lessen the suffering and stress, caused by the the psychotic symptoms. AIM: To introduce EMDR as a possible type of psychological treatment for patients suffering from psychosis-related imagery. METHOD: Three outpatients who had a psychotic disorder and suffered from auditory hallucinations and delusions were treated with EMDR in an average of six sessions. Treatment was performed by three therapists in different psychiatric institutions. All three were experienced in administrating CBT and EMDR. RESULTS: Treatment with EMDR reduced patients' level of anxiety, depression and the severity of psychotic symptoms. In addition, patients reported less avoidant behaviour and greater cognitive insight. CONCLUSION: The results of the study suggest that EMDR reduces the vividness and emotionality of imagery in psychosis which in turn alleviates the patients' psychotic symptoms. Further research into other possible types of interventions for the treatment of imagery in psychosis is recommended.

A meta-analysis of Hodgkin lymphoma reveals 19p13.3 TCF3 as a novel susceptibility locus.

Recent genome-wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified associations with genetic variation at both HLA and non-HLA loci; however, much of heritable HL susceptibility remains unexplained. Here we perform a meta-analysis of three HL GWAS totaling 1,816 cases and 7,877 controls followed by replication in an independent set of 1,281 cases and 3,218 controls to find novel risk loci. We identify a novel variant at 19p13.3 associated with HL (rs1860661; odds ratio (OR)=0.81, 95% confidence interval (95% CI) = 0.76-0.86, P(combined) = 3.5 × 10(-10)), located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment known to be involved in HL pathogenesis. This meta-analysis also notes associations between previously published loci at 2p16, 5q31, 6p31, 8q24 and 10p14 and HL subtypes. We conclude that our data suggest a link between the 19p13.3 locus, including TCF3, and HL risk.

Microneedle arrays for the transcutaneous immunization of diphtheria and influenza in BALB/c mice.

Transcutaneous immunization (TCI) is limited by poor permeation of macromolecules across the skin. Microneedle arrays form transient conduits and enhance the transport of vaccine molecules across the skin barrier without pain sensation. Here we investigated in mouse the immune responses after TCI using two model antigens, diphtheria toxoid (DT) and influenza subunit vaccine. The electric applicator enabled shorter microneedle (300 microm) to pierce mouse skin effectively, as shown by Trypan blue staining and trans-epidermal water loss measurement. The vaccines were topically applied with and without cholera toxin (CT) on microneedle-treated skin. In DT TCI, microneedle array pretreatment of the skin was essential to achieve substantial IgG and toxin-neutralizing antibody titers. Addition of CT further boosted the immune response to similar levels as observed after subcutaneous injection of AlPO4-adsorbed DT (DT-alum). In contrast, microneedle array pretreatment showed no effect on the immune response to plain influenza vaccine. This response was strongly improved by inclusion of CT, independent of microneedle treatment. These results indicate that TCI of DT and CT with microneedle treatment results in comparable protection as injection of DT-alum, and TCI of influenza vaccine adjuvanted with CT is superior to the injection of plain vaccine.

Tagging single-nucleotide polymorphisms in candidate oncogenes and susceptibility to ovarian cancer.

Low-moderate risk alleles that are relatively common in the population may explain a significant proportion of the excess familial risk of ovarian cancer (OC) not attributed to highly penetrant genes. In this study, we evaluated the risks of OC associated with common germline variants in five oncogenes (BRAF, ERBB2, KRAS, NMI and PIK3CA) known to be involved in OC development. Thirty-four tagging SNPs in these genes were genotyped in approximately 1800 invasive OC cases and 3000 controls from population-based studies in Denmark, the United Kingdom and the United States. We found no evidence of disease association for SNPs in BRAF, KRAS, ERBB2 and PIK3CA when OC was considered as a single disease phenotype; but after stratification by histological subtype, we found borderline evidence of association for SNPs in KRAS and BRAF with mucinous OC and in ERBB2 and PIK3CA with endometrioid OC. For NMI, we identified a SNP (rs11683487) that was associated with a decreased risk of OC (unadjusted P(dominant)=0.004). We then genotyped rs11683487 in another 1097 cases and 1792 controls from an additional three case-control studies from the United States. The combined odds ratio was 0.89 (95% confidence interval (CI): 0.80-0.99) and remained statistically significant (P(dominant)=0.032). We also identified two haplotypes in ERBB2 associated with an increased OC risk (P(global)=0.034) and a haplotype in BRAF that had a protective effect (P(global)=0.005). In conclusion, these data provide borderline evidence of association for common allelic variation in the NMI with risk of epithelial OC.

Validating genetic risk associations for ovarian cancer through the international Ovarian Cancer Association Consortium.

The search for genetic variants associated with ovarian cancer risk has focused on pathways including sex steroid hormones, DNA repair, and cell cycle control. The Ovarian Cancer Association Consortium (OCAC) identified 10 single-nucleotide polymorphisms (SNPs) in genes in these pathways, which had been genotyped by Consortium members and a pooled analysis of these data was conducted. Three of the 10 SNPs showed evidence of an association with ovarian cancer at P< or =0.10 in a log-additive model: rs2740574 in CYP3A4 (P=0.011), rs1805386 in LIG4 (P=0.007), and rs3218536 in XRCC2 (P=0.095). Additional genotyping in other OCAC studies was undertaken and only the variant in CYP3A4, rs2740574, continued to show an association in the replication data among homozygous carriers: OR(homozygous(hom))=2.50 (95% CI 0.54-11.57, P=0.24) with 1406 cases and 2827 controls. Overall, in the combined data the odds ratio was 2.81 among carriers of two copies of the minor allele (95% CI 1.20-6.56, P=0.017, p(het) across studies=0.42) with 1969 cases and 3491 controls. There was no association among heterozygous carriers. CYP3A4 encodes a key enzyme in oestrogen metabolism and our finding between rs2740574 and risk of ovarian cancer suggests that this pathway may be involved in ovarian carcinogenesis. Additional follow-up is warranted.

Improved piercing of microneedle arrays in dermatomed human skin by an impact insertion method.

An electrical applicator was designed, which can pierce short microneedles into the skin with a predefined velocity. Three different shapes of microneedles were used, namely 300 mum assembled hollow metal microneedle arrays, 300 mum solid metal microneedle arrays and 245 mum hollow silicon microneedle arrays. The latter are available as 4x4, 6x6 and 9x9 arrays. When using a velocity of 1 or 3 m/s reproducible piercing of dermatomed and full thickness human skin was evident from the appearance of blue spots on the dermal side of the skin after Trypan Blue treatment and the presence of fluorescently labeled particles in dermatomed skin. Manual piercing did not result in the appearance of blue spots. Transport studies revealed that i) piercing of microneedles with a predefined velocity into human skin resulted in a drastic enhancement of the Cascade Blue (CB, Mw 538) transport, ii) A higher piercing velocity resulted in a higher CB transport rate, iii) The CB transport rate was also dependent on the shape of the microneedles and iv) no difference in transport rate was observed between 4x4, 6x6 and 9x9 hollow silicon microneedle arrays.

Insulin-like growth factor-1 promoter polymorphisms and colorectal cancer: a functional genomics approach.

RATIONALE: Insulin-like growth factor-1 (IGF1) has been proposed to mediate the obesity-related carcinogenic effects of "Western lifestyle". While genetic factors explain at least half of inter-individual IGF1 variation, the IGF1 polymorphisms hypothesised to underlie the variation in cancer incidence rates remain ill-defined. METHODS: We used a comparative genomics approach to identify putative regulatory polymorphisms in the IGF1 promoter region within a rapidly westernising population, the Singapore Chinese. Association of IGF1 genotype with colorectal cancer risk was assessed among 298 colorectal cancer cases and 1142 controls nested within the Singapore Chinese Health Study. RESULTS: We identified a common (minor allele frequency = 0.36) single-nucleotide polymorphism (SNP), IGF1-2995 C/A, within a consensus domain for an octamer binding factor (Oct1/Oct2) transcription factor binding site. Possession of one or two copies of the minor allele (genotypes AA and CA) conferred an approximate 40% decrease in risk in comparison to genotype CC (odds ratio, 0.59; 95% confidence interval, 0.45 to 0.77). This association was stronger for colon cancer than for rectal cancer (p(heterogeneity)<0.001) and for those who were physically active versus inactive (p(interaction) = 0.05). Models including other previously identified promoter polymorphisms did not provide a better prediction of colorectal cancer risk. CONCLUSIONS: Our results support the hypotheses that IGF1 plays a role in colonic carcinogenesis and that genetically inherited variation in IGF1 expression influences risk of colorectal cancer.

Assembled microneedle arrays enhance the transport of compounds varying over a large range of molecular weight across human dermatomed skin.

In this study, we demonstrate the feasibility to use microneedle arrays manufactured from commercially available 30G hypodermal needles to enhance the transport of compounds up to a molecular weight of 72 kDa. Piercing of human dermatomed skin with microneedle arrays was studied by Trypan Blue staining on the SC side of the skin and transepidermal water loss measurements (TEWL). Passive transport studies were conducted with Cascade Blue (CB, Mw 538), Dextran-Cascade Blue (DCB, Mw 10 kDa), and FITC coupled Dextran (FITC-Dex, Mw 72 kDa). Microneedle arrays with needle lengths of 900, 700 and 550 micro m are able to pierce dermatomed human skin as evident from (a) the appearance of blue spots on the dermal side of the skin after Trypan Blue treatment and (b) elevated TEWL levels after piercing compared to non-treated human dermatomed skin. Microneedles with a length of 300 micro m did not pierce human skin in vitro. Transport studies performed with model compounds ranging from 538 Da to 72 kDa revealed that pretreatment with microneedle arrays enhanced the transport across dermatomed human skin. However, some degradation was also observed for FITC-Dex and DCB. We conclude that assembled microneedle arrays can be used to deliver compounds through the skin up to a molecular weight of at least 72 kDa.

Interaction between cyclooxygenase-2 gene polymorphism and dietary n-6 polyunsaturated fatty acids on colon cancer risk: the Singapore Chinese Health Study.

This case-control study of 310 colorectal cancer cases and 1177 controls in a nested prospective, population-based cohort of Singapore Chinese subjects found a statistically significant association between the cyclooxygenase (COX)-2 -765G>C gene polymorphism and colon cancer risk among high consumers of dietary n-6 polyunsaturated fatty acids (odds ratio=2.38, 95% confidence interval=1.23-4.59).

Apolipoprotein E protects against neuropathology induced by a high-fat diet and maintains the integrity of the blood-brain barrier during aging.

SUMMARY: The present study provides evidence that chronic intake of a high-fat diet induces a dramatic extravasation of immunoglobulins, indicating alterations in blood-brain barrier (BBB) functioning, in the brains of apolipoprotein E (apoE)-knockout mice, but not of C57Bl/6 control mice. Using sodium fluorescein as a marker for the permeability of the BBB, we found additional support for age-related disturbances of BBB function in apoE-knockout mice. Behavioral analysis of apoE-knockout mice compared with C57Bl/6 mice indicated that they were also less efficient in acquiring the spatial Morris water maze task. Furthermore, apoE-knockout mice are known to develop severe atherosclerosis, which is exacerbated with a high-fat diet. We therefore compared the apoE-knockout mice with the apoE3-Leiden transgenic mice, which are known to develop atherosclerosis. However, apoE3-Leiden mice that were kept on a high-fat, high-cholesterol diet and that developed atherosclerosis to an extent similar to the apoE-knockout mice, showed no signs of BBB disturbances. These results indicate for the first time that apoE plays an essential role in the maintenance of the integrity of the BBB during aging and that it protects the brain from neuropathology induced by a high-fat diet. We therefore hypothesize that the role of apoE in the maintenance of the integrity of the BBB may be the mechanism by which apoE affects the progression of neurodegeneration, as seen in Alzheimer's disease.

A genome screen of families with multiple cases of prostate cancer: evidence of genetic heterogeneity.

We conducted a genomewide screen for prostate cancer-susceptibility genes on the basis of data from 98 families from the United States and Canada that had three or more verified diagnoses of prostate cancer among first- and second-degree relatives. We found a statistically significant excess of markers for which affected relatives exhibited modest amounts of excess allele-sharing; however, no single chromosomal region contained markers with excess allele-sharing of sufficient magnitude to indicate unequivocal evidence of linkage. Positive linkage signals of nominal statistical significance were found in two regions (5p-q and 12p) that have been identified as weakly positive in other data sets and in region 19p, which has not been identified previously. All these signals were considerably stronger for analyses restricted to families with mean age at onset below the median than for analyses of families with mean age at onset above the median. The data provided little support for any of the putative prostate cancer-susceptibility genes identified in other linkage studies.