Practice question

In human pedigree studies, individual who first brings family to attention of geneticist due to phenotype is designated proband or propositus/proposita, marked by arrow. Pedigree construction starts from proband, then extends upward to parents, sideways to sibs, and downward to children to evaluate inheritance pattern comprehensively. Ancestor refers to earlier generation member, carrier denotes heterozygous recessive individual with normal phenotype, and index allele term relates to molecular variant. Identifying proband provides consistent reference point for collecting family history and calculating recurrence risks.