Standardised pedigree symbols and nomenclature

Wellcome Connecting Science | Graphic | Empowering People: Genetic Counselling in Focus

In the 1990s a standardised set of symbols was developed and agreed for use in drawing pedigrees. The purpose was to create a common language that would make the details of a diagram recognisable and intelligible to anyone accessing the information. Whether drawing by hand or using computer software, the same symbols are used. They show details such as biological sex, whether someone is affected by a condition (and their age of diagnosis), and if someone is alive or not. They can also include information about social relationships (e.g. divorce or adoption) as well as gender identification.