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How to Draw a Pedigree

PDF icon IIHG How to Draw a Pedigree.pdf

Please follow the instructions below when creating a pedigree.

  1. Bennett RL, French KS, Resta RG, Austin J. Practice resource-focused revision: Standardized pedigree nomenclature update centered on sex and gender inclusivity: A practice resource of the National Society of Genetic Counselors. J Genet Couns. 2022 Dec;31(6):1238-1248. doi: 10.1002/jgc4.1621. Epub 2022 Sep 15. PMID: 36106433.
  2. Bennett, R.L., French, K.S., Resta, R.G. & Doyle, D.L. Standardized human pedigree nomenclature: update and assessment of the recommendations of the National Society of Genetic Counselors. J Genet Couns 17, 424-33 (2008).

The following information must be included on the pedigree:

  • First name or initials of relatives (To maintain confidentiality do NOT use full names; alternatively, use generation-individual numbers (I-1, I-2, II-1). Please limit identifying information to be compliant with HIPAA guidelines.)
  • Affected status (i.e. who in the family has disease) for each individual in the family
  • Age of all family members, or age at death (To be compliant with HIPAA guidelines, please do not submit a full birth date at this time.)
  • Whether individuals are living or deceased. Cause of death, if known, should be indicated below the symbol.
  • Residence for all family members (City, State)
  • Willingness to participate in the study (indicate with an asterisk)
  • Key to shading of symbols
  • Adoption status
  • Consanguinity (i.e. parents are related)
  • Race and ethnicity
  • Date pedigree obtained

General guidelines:

  • It is helpful to start in the middle of the page when drawing a pedigree.
  • Male partners are to the left of female partners.
  • Siblings are drawn from oldest to youngest with the oldest listed on the left and the youngest on the right.
  • If there are multiple disorders or diseases, use quadrants or different shading (solid, cross-hatching) to indicate each disease (see examples)

Example Pedigrees

Basic Pedigree Lines