Pedigree analysis is the study of patterns of inheritance of traits within families over multiple generations. Pedigrees are diagrams that show the relationships among family members and the transmission of genetic traits over time. Pedigree analysis can be used to determine whether a trait is inherited in a Mendelian fashion, to predict the likelihood of an individual inheriting a particular trait, and to identify the genetic basis of a particular trait.
In a pedigree diagram, circles represent females and squares represent males. An individual who is affected by the trait of interest is shaded in, while an individual who does not have the trait is left unshaded. Arrows are used to indicate the direction of the family lineage.
Pedigrees can be used to determine the mode of inheritance of a particular trait, which can be autosomal (inherited on non-sex chromosomes), sex-linked (inherited on sex chromosomes), or mitochondrial (inherited through the mother). By analyzing patterns of inheritance within a family, pedigree analysis can be used to predict the likelihood of an individual inheriting a particular trait and to identify the genetic basis of the trait.
Pedigree analysis is a useful tool in genetic counseling, where it can be used to help individuals and families understand their risk of inheriting a particular trait and to make informed decisions about family planning. It is also used in medical research to identify the genetic basis of inherited diseases and to develop treatments for genetic disorders.