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Any difference between the sequence of two individuals’ genomes or a reference genome. Variants can be harmless or disease causing (pathogenic).

Use in clinical context

Variants in an individual’s genome can be the direct cause of a rare condition, result in an increased or decreased predisposition to developing common health problems, or they can have no discernible phenotypic effect at all. A variant can be a single base change or span many thousands of bases. The size of the variant does not reflect the impact, if any, that it has on the individual.

Last updated on 5th June, 2019