[Drawing up pedigrees: symbols and meanings].

Inquiring of and gathering family history to establish a pedigree is the basic work to assess the health status of a whole family for clinical services or studies in genetics. Pedigrees, moreover, can show not only the disease circumstances of individuals but also the consanguinity/social relationships between the family members. They can be used to assist clinical professionals to make diagnoses and identify potential risk cases, to whom genetic counseling services could be provided. In addition, pedigrees can help researchers to discover novel genetic diseases and confirm the inheritance patterns and mechanisms. In education, through learning the skills for gathering the materials required to establish pedigree, students can develop the ability to assess the health status of each family member and identify the lifestyle or risk factors affecting health promotion. In addition, through their composition from simple symbols and lines, pedigrees are becoming an international language. Therefore, in 1995, the National Society of Genetic Counseling (USA) proposed recommendations for standardized human pedigree nomenclature. This article provides a brief introduction to standard pedigrees, as well as an account of a case to illustrate how to apply the nomenclature in practice. With the completion of the Human Genome Project in 2001, standardized pedigrees have undoubtedly become the best language through which medical or genomic professionals can communicate and share the latest discoveries.