Epigenome analysis of neonatal blood spots

Changes in DNA methylation, is one mechanism by which genes are regulated. Aberrant methylation can lead to gene dysregulation, such as inactivation of tumour suppressor genes, and is observed in all cancers. Gene dysregulation via aberrant DNA methylation may be an important contributor to disease outcomes. Importantly, these marks are malleable in response to environmental exposures and contribute to phenotypic plasticity in the context of a fixed genotype. Many studies suggest maternal exposures during pregnancy can have a profound impact on the epigenome and so determine gene expression patterns and health throughout the life-course. Studies of altered epigenetic marking are of profound importance for mechanistic understanding of the role of exposures on health but especially for studies of the developmental origins of health. Historically collected neonatal blood spot samples represent a rich resource in which methylation at birth could be measured decades after being sampled and methylation patterns associated with recorded disease outcomes. Here we aimed to test the feasibility that methylation could be assessed in historically collected blood spot samples and assess if the time since sample collection affected methylation patterns. The Newcastle Haematology biobank houses blood spots collected routinely from neonates 5-8 days after birth between the years 1984-1994 in the local region. Samples were selected from across the collection period and cross referenced with the Northern region Children's malignant disease registry in an aim to exclude samples from children who had gone on to have a malignancy during childhood. Genome-wide DNA methylation profiling of neonatal blood spots was assessed using the Illumina Infinium® MethylationEPIC BeadChip platform. Extraction yield DNA of sufficient quality and quantity for successful analysis of DNA methylation. Time since collection was not found to significantly influence methylation in this sample. Data from this study could be utilised in future case-controls studies to investigate the relationship between methylation patterns and birth and disease outcomes. Genome-wide DNA methylation profiling of neonatal blood spot sample taken from heel pricks 2-7 days after birth were assessed Bisulphite converted DNA extracted from neonatal blood samples were hybridized to Illumina Infinium MethylationEPIC BeadChips