Using a moderate-sized cohort selected with extreme BMD (n = 344; absolute value BMD, 1.5-4.0), significant association of several members of the Wnt signaling pathway with bone densitometry measures was shown. This confirms that extreme truncate selection is a powerful design for quantitative trait association studies of bone phenotypes.Introduction: Although the high heritability of BMD variation has long been established, few genes have been conclusively shown to affect the variation of BMD in the general population. Extreme truncate selection has been proposed as a more powerful alternative to unselected cohort designs in quantitative trait association studies. We sought to test these theoretical predictions in studies of the bone densitometry measures BMD, BMC, and femoral neck area, by investigating their association with members of the Wnt pathway, some of which have previously been shown to be associated with BMD in much larger cohorts, in a moderate-sized extreme truncate selected cohort (absolute value BMD Z-scores ‫ס‬ 1.5-4.0; n ‫ס‬ 344). Conclusions: This study shows that polymorphisms of multiple members of the Wnt pathway are associated with BMD variation. Furthermore, this study shows in a practical trial that study designs involving extreme truncate selection and moderate sample sizes can robustly identify genes of relevant effect sizes involved in BMD variation in the general population. This has implications for the design of future genome-wide studies of quantitative bone phenotypes relevant to osteoporosis.

Nuclear protein in testis (NUT)-midline carcinoma (NMC) is a rare, aggressive disease typically presenting with a single t(15;19) translocation that results in the generation of a bromodomain-containing protein 4 (BRD4)-NUT fusion. PER-624 is a cell line generated from an NMC patient with an unusually complex karyotype that gave no initial indication of the involvement of the NUT locus. Analysis of PER-624 next-generation transcriptome sequencing (RNA-Seq) using the algorithm FusionFinder identified a novel transcript in which Exon 15 of BRD4 was fused to Exon 2 of NUT, therefore differing from all published NMC fusion transcripts. The three additional exons contained in the PER-624 fusion encode a series of polyproline repeats, with one predicted to form a helix. In the NMC cell line PER-403, we identified the 'standard' NMC fusion and two novel isoforms. Knockdown by small interfering RNA in either cell line resulted in decreased proliferation, increased cell size and expression of cytokeratins consistent with epithelial differentiation. These data demonstrate that the novel BRD4-NUT fusion in PER-624 encodes a functional protein that is central to the oncogenic mechanism in these cells. Genomic PCR indicated that in both PER-624 and PER-403, the translocation fuses an intron of BRD4 to a region upstream of the NUT coding sequence. Thus, the generation of BRD4-NUT fusion transcripts through post-translocation RNA-splicing appears to be a common feature of these carcinomas that has not previously been appreciated, with the mechanism facilitating the expression of alternative isoforms of the fusion. Finally, ectopic expression of wild-type NUT, a protein normally restricted to the testis, could be demonstrated in PER-403, indicating additional pathways for aberrant cell signaling in NMC. This study contributes to our understanding of the genetic diversity of NMC, an important step towards finding therapeutic targets for a disease that is refractory to current treatments.

Low Apgar score has been associated with higher risk for several neurological and psychiatric disorders, including cerebral palsy and intellectual disability. Studies of the association between Apgar score and autism spectrum disorder (ASD) have been inconsistent. We aimed to investigate (1) the association between low Apgar score at 5 min and risk for ASD, and (2) the modifying effects of gestational age and sex on this association in the largest multinational database of ASD. We included prospective data from 5.5 million individuals and over 33,000 cases of ASD from Norway, Sweden, Denmark and Western Australia who were born between 1984 and 2007. We calculated crude and adjusted risk ratios (RR) with 95% confidence intervals (95% CIs) for the associations between low Apgar score and ASD. All analyses for ASD were repeated for autistic disorder (AD). We used interaction terms and stratified analysis to investigate the effects of sex, gestational age, and birth weight on the association. In fully adjusted models, low Apgar scores (1–3) (RR, 1.42; 95% CI, 1.16–1.74), and intermediate Apgar scores (4–6) (RR, 1.50; 95% CI, 1.36–1.65) were associated with a higher RR of ASD than optimal Apgar score (7–10). The point estimates for low (RR, 1.88; 95% CI, 1.41–2.51) and intermediate Apgar score (RR, 1.54; 95% CI, 1.32–1.81) were larger for AD than for ASD. This study suggests that low Apgar score is associated with higher risk of ASD, and in particular AD. We did not observe any major modifying effects of gestational age and sex, although there seems to be substantial confounding by gestational age and birth weight on the observed association. Electronic supplementary material The online version of this article (10.1007/s10654-018-0445-1) contains supplementary material, which is available to authorized users.