| BCS70 | The 1970 British Cohort Study. |
| DNA methylation | DNA Methylation is a biochemical process that involves the addition of a methyl group (CH3) to the DNA molecule. This modification typically (but not exclusively) occurs at cytosine bases in a specific sequence context (CpG sites, where cytosine is followed by guanine). DNA methylation serves as an epigenetic mechanism, generally regulating gene expression by silencing genes, but it can also repress the associated genes depending on where it occurs in the DNA sequence. These methylation patterns are crucial for normal development, cellular differentiation, and the control of various biological processes. Dysregulation of DNA methylation can contribute to diseases and disorders. |
| Exome | The exome refers to the subset of an organism’s DNA that contains the protein-coding genes. These genes are responsible for producing the proteins that carry out various functions in the body. The exome makes up only about 1-2% of the entire DNA in an organism, yet it plays a vital role in determining an individual’s traits and susceptibility to genetic disorders and ~85% of identified disease causing variants reside in the exome. Studying the exome is often of particular interest in genetics and genomics research because mutations in these protein-coding genes can lead to a wide range of inherited diseases and conditions. |
| Whole exome sequencing | Whole exome sequencing (WES) is a DNA sequencing technique that focuses on sequencing the exome. WES involves sequencing all the exons, which are the coding regions of genes, to identify genetic variations or mutations that may be linked to specific diseases or traits. WES offers higher resolution when studying variations within genes compared to array based methods and therefore can be used to identify rare variants of low frequency. This approach provides a cost-effective way to analyze a substantial portion of an individual’s genetic information, making it valuable for both research and clinical applications, particularly in the study of genetic disorders. |
| Imputed data | Genotype imputation is the term used to describe the process of inferring unobserved genotypes in a sample of individuals. It is achieved by using known haplotypes in a population (e.g. HapMap, the 1000 Genomes Project or TOPMed in humans). Data which has undergone imputation is known as imputed data. |
| MCS | Millenium Cohort Study. |
| NCDS | National Child Development Study. |
| PGI | PGI (polygenic indexes, also termed “polygenic scores” or “polygenic risk scores”) summarise into a single score, the number of genetic variants an individual has linked to a particular trait. |
| QC | Quality control -the steps taken to monitor and control the quality of a product. In this case, the ‘product’ is a set of genetic data produced for the purpose of detecting genotype-phenotype associations and gene-environment interactions. |