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The word pedigree is a corruption of the Anglo-Norman French pé de grue or "crane's foot", either because the typical lines and split lines (each split leading to different offspring of the one parent line) resemble the thin leg and foot of a crane [3] or because such a mark was used to denote succession in pedigree charts. [4] A pedigree ...
A genogram, also known as a family diagram, [1] [2] is a pictorial display of a person's position and ongoing relationships in their family's hereditary hierarchy. It goes beyond a traditional family tree by allowing the user to visualize social patterns and psychological factors that punctuate relationships, especially patterns that repeat over the generations.
An ancestry chart, which is a tree showing the ancestors of an individual and not all members of a family, will more closely resemble a tree in shape, being wider at the top than at the bottom. In some ancestry charts, an individual appears on the left and his or her ancestors appear to the right.
An example pedigree chart of the inheritance of a sex-linked disorder. Each child of a mother affected with an X-linked dominant trait has a 50% chance of inheriting the mutation and thus being affected with the disorder.
Pedigrees are used to help detect many different genetic diseases. A pedigree can also be used to help determine the chances for a parent to produce an offspring with a specific trait. Four different traits can be identified by pedigree chart analysis: autosomal dominant, autosomal recessive, x-linked, or y-linked.
This term is restricted to autosomal traits, and should not be confused with sex-linked characteristics, which have to do with genetic differences on the sex chromosomes (see sex-determination system). Sex-limited genes are also distinguished from sex-influenced genes, where the same gene will show differential expression in each sex.
(It is conventional in genetics to use capital letters to indicate dominant alleles and lower-case letters to indicate recessive alleles.) The probability of an individual offspring's having the genotype BB is 25%, Bb is 50%, and bb is 25%. The ratio of the phenotypes is 3:1, typical for a monohybrid cross. When assessing phenotype from this ...
Genealogy (from Ancient Greek γενεαλογία (genealogía) 'the making of a pedigree') [2] is the study of families, family history, and the tracing of their lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kinship and pedigrees of ...