Infinium 850k Beadchip analysis of control human brain for copy number mosaicism

Copy number mosaicism in the human brain has been reported recently by several authors. This experiment was performed to further investigate our preliminary data of apparent widespread deletions in brain DNA, detected in a custom Agilent aCGH designed for Parkinson's disease (PD) genes in both patients and controls, and supported by droplet digital PCR. To avoid any effect of diseased tissue, we used only controls here. All DNA was freshly extracted. A validated SNP array was chosen to ensure that our results were not due to artefacts specific to the aCGH design used, with SNP array giving the additional advantage of B allele frequency estimation. Seven DNA samples were analysed, from four healthy individuals whose brain had been fresh frozen. The cerebellum and frontal cortex were analysed from three, and the cerebellum only for one.