Project description:The offspring of older fathers have an increased risk of neurodevelopmental disorders such as schizophrenia and autism. It has been proposed that de novo point mutations and copy number variants (CNVs) in the continually dividing spermatogonia underlie this association. In light of the evidence implicating CNVs with schizophrenia and autism, here we use a mouse model to test the hypothesis that the offspring of older males have an increased risk of de novo CNVs. Three-month-old and fourteen- to sixteen-month-old C57BL/6J sires were mated with three-month-old dams to create control offspring and offspring of old sires, respectively. Applying genome-wide microarray screening technology, seven distinct CNVs were identified in a discovery set of twelve offspring and their parents. Competitive quantitative PCR was employed to confirm the variants and establish their frequency in a replication set of 77 offspring and their parents. Six de novo CNVs were detected in the offspring of older sires, while none were detected in the control group. One of the de novo CNVs involved Auts2 (autism susceptibility candidate 2), and other CNVs included genes linked to schizophrenia, autism and brain development. Two of the CNVs were associated with behavioural and/or neuroanatomical phenotypic features. This is the first experimental demonstration that the offspring of older males have more de novo CNVs. The results suggest that offspring of older fathers may be at increased risk of neurodevelopmental disorders such as schizophrenia and autism via the generation of de novo CNV in the male germline. In light of the trends for delayed parenthood in many societies, and in light of the potential for these CNVs to accumulate over subsequent generations, the impact of these mechanisms on the health of future generations warrants closer scrutiny. 2 sires of advanced paternal age (12-16 months of age) and 2 control (3 months of age) sires were mated to dams (3 months of age) to create 6 offspring of advanced paternal age (APA) and 6 control offspring (C), respectively, with an even number of sexes within each group of offspring. A commerical aCGH and a custom CNV array (both supplied by Agilent) were used in combination to detect copy number variations in the genomes of the offspring and their parents. DNA from all male animals was hybridized against a male reference animal and that from all female animals against a female reference animal.

Project description:Less than 30% of children with high-risk (HR) metastatic neuroblastoma (NB) show a long survival (Pearson 2000). In order to identify novel molecular prognostic markers useful to better predict patientsM-bM-^@M-^Y relapse risk estimation, we performed genome- and/or transcriptome-wide analyses of 129 stage 4 HR-NBs. This is the largest study for this NB subtype. Children older than 1 year of age at diagnosis were categorized as M-bM-^@M-^\short-survivorsM-bM-^@M-^] (dead of disease within 5 years from diagnosis) and M-bM-^@M-^\long-survivorsM-bM-^@M-^] (alive with an overall survival time > 5 years). A significant correlation of patient survival with the presence of small number of segmental copy number aberrations (CNA < 3) was observed. Thus, within the group of stage 4 HR-NBs, we identified a specific subgroup of patients (those with highest number of CNA) that have a higher risk of progression/recurrence. The complex genomic pattern is an independent prognostic marker, since MYCN oncogene amplification only affects the predictive value of single CNA (i.e., 1p loss, 17q gain). Integrative analysis of genomic and expression signatures demonstrated that fatal outcome is associated with loss of cell cycle control and with progression of tumor due to deregulation of Rho GTPase signaling and genes related to cell motility. Tumors with MYCN amplification showed a lower chromosome instability compared to MYCN-single copy NBs (P=0.0008), dominated by 17q gain and 1p loss. Moreover, our results suggest that the MYCN amplification mainly drives the disruption of neuronal differentiation and the reduction of cell adhesion process involved in tumor invasion and metastasis. For array-CGH profiling, we analyzed 91 samples of metastatic neuroblastomas. All patients were classified as stage 4 and they were older than 1 year of age at time of diagnosis. Regarding the clinical course, 46 were short-survivors (dead of disease within 60 months from diagnosis. Deaths due to toxicity were censored) and 45 were long-survivors (alive with an overall survival time > 60 months). This submission consists of 22 new samples and 69 other cases previously deposited in GEO under Series accessions GSE14109 and GSE25771.

Dataset Information

The Leiden Longevity Study: Identification of biomarkers of the rate of ageing

Publications

Nonagenarian siblings and their offspring display lower risk of mortality and morbidity than sporadic nonagenarians: The Leiden Longevity Study.

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