Use in clinical context
When a whole genome or part of a genome is sequenced a reference is needed for comparison to identify any variants that might provide answers to the question. Reference genomes are often works in progress and are updated as more genomes of that particular species are sequenced. As they are constructed from a number of individuals, the reference can be considered ‘normal’ because variable sites are identified and the predominant variant at each determined. While considered ‘normal’, reference genomes do have limitations as they may not be representative for whole species, for example the human reference genome is predominantly a composite of Caucasian genomes.