Improving Genetic Prediction by Leveraging Genetic Correlations Among Human Diseases and Traits

Genomic prediction has the potential to contribute to precision medicine. However, to date, the utility of such predictors is limited due to low accuracy for most traits. Here theory and simulation study are used to demonstrate that widespread pleiotropy among phenotypes can be utilised to improve genomic risk prediction. We show how a genetic predictor can be created as a weighted index that combines published genome-wide association study (GWAS) summary statistics across many different traits. We apply this framework to predict risk of schizophrenia and bipolar disorder in the Psychiatric Genomics consortium data, finding substantial heterogeneity in prediction accuracy increases across cohorts. For six additional phenotypes in the UK Biobank data, we find increases in prediction accuracy ranging from 0.7 for height to 47 for type 2 diabetes, when using a multi-trait predictor that combines published summary statistics from multiple traits, as compared to a predictor based only on one trait. © 2018 The Author(s)

Age at first birth in women is genetically associated with increased risk of schizophrenia

Prof. Paunio on PGC:n jäsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe

Monitoring mortality as an indicator of influenza in Catalonia, Spain.

This study aimed to investigate the behaviour of two indicators of influenza activity in the area of Barcelona and to evaluate the usefulness of modelling them to improve the detection of influenza epidemics. DESIGN: Descriptive time series study using the number of deaths due to all causes registered by funeral services and reported cases of influenza-like illness. The study concentrated on five influenza seasons, from week 45 of 1988 to week 44 of 1993. The weekly number of deaths and cases of influenza-like illness registered were processed using identification of a time series ARIMA model. SETTING: Six large towns in the Barcelona province which have more than 60,000 inhabitants and funeral services in all of them. MAIN RESULTS: For mortality, the proposed model was an autoregressive one of order 2 (ARIMA (2,0,0)) and for morbidity it was one of order 3 (ARIMA (3,0,0)). Finally, the two time series were analysed together to facilitate the detection of possible implications between them. The joint study of the two series shows that the mortality series can be modelled separately from the reported morbidity series, but the morbidity series is influenced as much by the number of previous cases of influenza reported as by the previous mortality registered. CONCLUSIONS: The model based on general mortality is useful for detecting epidemic activity of influenza. However, because there is not an absolute gold standard that allows definition of the beginning of the epidemic, the final decision of when it is considered an epidemic and control measures recommended should be taken after evaluating all the indicators included in the influenza surveillance programme

More Judicious Use of Expectant Management for Localized Prostate Cancer during the Last 2 Decades

Urologists have been criticized for overtreating men with low risk prostate cancer and for passively observing older men with higher risk disease. Proponents of active surveillance for low risk disease and critics of watchful waiting for higher risk disease have advocated for more judicious use of observation. Thus, we compared 2 population based cohorts to determine how expectant management has evolved during the last 2 decades. A total of 5,871 men with localized prostate cancer were enrolled in the PCOS (Prostate Cancer Outcomes Study) or the CEASAR (Comparative Effectiveness Analysis of Surgery and Radiation) study. We compared the use of definitive treatment vs expectant management (watchful waiting or active surveillance) across cohorts, focusing on the influence of disease risk, age and comorbidities. Use of watchful waiting or active surveillance was similar in PCOS and CEASAR (14% in each). Compared to the PCOS, more men in the CEASAR study with low risk disease selected watchful waiting or active surveillance (25% vs 15%, respectively), whereas fewer men with intermediate (7% vs 14%) and high risk (3% vs 10%) disease chose watchful waiting or active surveillance (p <0.001 for each). The association of disease risk with watchful waiting or active surveillance was significantly larger in CEASAR than in PCOS (OR 7.3, 95% CI 3.4 to 15.7). Older age was associated with watchful waiting or active surveillance in both cohorts but there was no association between comorbidity and watchful waiting or active surveillance in the CEASAR study. Use of watchful waiting or active surveillance was more aligned with disease risk in CEASAR compared to PCOS, suggesting there has been a pivot from watchful waiting to active surveillance. While older men were more likely to be observed, comorbidity had little, if any, influence