3.24: Understand How to Interpret Family Pedigrees

FAMILY PEDIGREES: Chart of genetic history of a family over several generations

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• Males are represented as Squares, Females are represented as circles
• Shaded symbol indicates an individual is affected by stated condition, unshaded symbol indicates an individual is unaffected

EXAMPLE: HUNTINGTON’S DISEASE

Diagram showing an Example of Family Pedigree for Huntington's Disease

DESCRIPTION	NUMBER OF PEOPLE WHO FIT THE DESCRIPTION
MALE MALE WITH DISEASE	7 2
FEMALE FEMALE WITH DISEASE	6 2
HOMOZYGOUS RECESSIVE	11
HETEROZYGOUS	4
HOMOZYGOUS DOMINANT	0