Huntington disease pedigree.

This simple pedigree shows an autosomal dominant pattern using Huntington disease as the clinical example. An affected parent has an affected child in the next generation, while unaffected relatives are also shown so the family structure is easy to read. The affected granddaughter is the proband, the person whose history brought the family to clinical attention. This is the kind of compact drawing used early in a consultation or in genetics teaching, before dates, test reports and additional relatives are added. A pedigree shows reported family history and relationships; it cannot determine whether a person has inherited a variant. Genetic testing and medical decisions should be discussed with a qualified clinician or counselor.