Pedigree Drawing

Drawing a Pedigree for Your Family

Follow these simple instructions to draw a pedigree for your family that includes you and your first degree relatives. You can then expand the pedigree as far out into your family as you want, following the same pattern.

A note before you start:
Only your relatives by blood need to be included in this pedigree. Do not include any relatives by adoption. Also do not include any relatives by marriage, such as your spouse or a step-parent’s children from a previous marriage. Only blood relatives, not relatives by marriage, share their genetic material with you. Leaving off relatives by marriage makes the pedigree much simpler to draw.

 

Step-by-step instructions:

1. Start with a blank piece of paper. In the middle of page, draw a square if you are male, a circle if you are female. Note your name or initials and your age under the symbol.
   Example:
   
   
   
   
   
   
2. Add symbols for your (biological) parents. Use a circle for your mother and a square for your father. Draw a diagonal line through the symbol for an individual who has died and note the age at death. Note how the lines connecting the symbols indicate the parent-child relationship.
   Example:
   
   
   
   
   
   
3. Add symbols for your siblings. Use circles for sisters and squares for brothers. As mentioned before, do not include any siblings by adoption or by marriage, such as a step-parent’s children from a previous marriage. Note how the lines indicate sibling relationship.
   Example:
   
   
   
   
   
   
4. Add symbols for half-siblings. Note how the symbol for the half-sibling is only connected to one parent. You do not need to add the half-sibling’s other parent, unless that parent is related to you by blood.
   Example:
   
   
   
   
   
   
5. Add symbols for your children. Note the special symbols for identical twins. Note that you do not need to add a symbol for your spouse, unless your spouse is related to you by blood (eg, if your spouse is your cousin).
   Example:
   
   
   
   
   
   
6. Fill in the symbols for family members who have received a diagnosis of the familial disease. Note the age at diagnosis in parenthesis. Use an arrow to indicate the index patient for the family, ie, the family member in whom the familial mutation was first identified.
   Example: