Identification of common genetic risk variants for autism spectrum disorder

Autism spectrum disorder (ASD) is a highly heritable and heterogeneous group of neurodevelopmental phenotypes diagnosed in more than 1% of children. Common genetic variants contribute substantially to ASD susceptibility, but to date no individual variants have been robustly associated with ASD. With a marked sample-size increase from a unique Danish population resource, we report a genome-wide association meta-analysis of 18,381 individuals with ASD and 27,969 controls that identified five genome-wide-significant loci. Leveraging GWAS results from three phenotypes with significantly overlapping genetic architectures (schizophrenia, major depression, and educational attainment), we identified seven additional loci shared with other traits at equally strict significance levels. Dissecting the polygenic architecture, we found both quantitative and qualitative polygenic heterogeneity across ASD subtypes. These results highlight biological insights, particularly relating to neuronal function and corticogenesis, and establish that GWAS performed at scale will be much more productive in the near term in ASD.Peer reviewe

Using complex plant pedigrees to map valuable genes

Statistical methods pioneered by human and animal geneticists use marker and pedigree information to detect quantitative trait loci within complex pedigrees. These methods, adapted to plants, promise to expand the range of data useful for identifying the genetic factors influencing plant growth, development and evolutionary responses, and to increase the relevance and cost effectiveness of quantitative trait loci mapping in applied contexts.

Aantalontwikkelingen van wadvogels in de Nederlandse Waddenzee in 1990-2008 : verschillen tussen oost en west (themanummer Waddenzee)

In het begin van de jaren negentig werd de Waddenzee getroffen door de grote schelpdiercrisis. Droogvallende mosselbanken verdwenen bijna allemaal en de kokkelbestanden bereikten een historisch dieptepunt. Sindsdien zijn de schelpdierbestanden op de droogvallende platen beter beschermd en heeft ook herstel plaatsgevonden. Je zou verwachten dat dit doorwerkt in de aantallen wadvogels die de Waddenzee bevolken. Maar is dat ook zo?. Een bijdrage van SOVON en IMARE

External validation of prognostic models for ongoing pregnancy after in-vitro fertilization

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[Methods and results of in-vitro fertilisation in the Netherlands in the years 1983-1994]

Item does not contain fulltextOBJECTIVE: To describe methods and results of in-vitro fertilisation (IVF) treatment during the first 12 years after the introduction of IVF treatment in the Netherlands. Design. Retrospective cohort study. METHOD: A nationwide study was conducted among women who had had their first IVF cycle stimulated with gonadotrophins in 12 IVF centres in the Netherlands in the period 1 January 1983 to 31 December 1994 (n = 8, 184). RESULTS: The subfertility diagnosis related to tubal factors decreased from 70% in 1987 to 25% in 1994. The subfertility diagnosis related to a male factor increased from 8.7% in 1987 to 35.5% in 1994. The mean age at first IVF treatment remained roughly constant. During the introduction of GnRH agonists there was an increase in gonadotrophin dosages, the number of retrieved oocytes, the number of high responders and/or women who experienced an ovarian hyperstimulation syndrome (OHSS). The percentage of deliveries with at least one baby born alive after the first IVF cycle increased from 6% in 1984 to 18% in 1994. The number of live births per 100 transferred embryos increased from 2.5 in 1985 to 12 in 1994. Furthermore, the mean numbers of embryos transferred after the first IVF cycle decreased from 3.2 in 1987 to 2.2 in 1994. The overall success rate - defined as the proportion of women who had at least one child born alive after one or more IVF cycles - for women who had their first IVF treatment between 1983 and 1994 was 37.1%. The percentage of triplets or quadruplets decreased from 8.7 in 1989 to 1.2 in 1994. The percentage of twin deliveries remained about 25. CONCLUSION: The introduction of GnRH agonists and the higher dosages of gonadotrophins led to a higher oocyte harvest. During the first years of IVF treatment there was an increase in the success rate after the first treatment cycle. The overall success rate remained constant after 1991. The risk of developing an OHSS increased whereas the rate of twin deliveries remained constant