Twins
Two lines to two children that start from the same point on the parents’ line mean twins. A short bar joining the two lines marks identical twins.
How to read it
The University of North Dakota’s guide connects twins to one another, with a single line connecting their line to the parents’ line, so the pair hang from an upside-down V. On the Multicultural Family Institute’s sheet a bar across the V marks identical twins, a form Washburn University’s guide labels identical, maternal or monozygotic twins. Twins otherwise take their place among the Children in birth order.
Also searched as: genogram twins, identical twins, twins genogram, twins symbol.
This explains what a symbol records on a genogram. Clinicians vary the notation, and a genogram’s own key takes precedence.
Twins in the medical pedigree
The National Society of Genetic Counselors’ pedigree uses the same bar for monozygotic twins and a question mark between the lines when it isn’t known. Twins with neither are taken to be dizygotic. Triplets are drawn the same way, with three lines from one point.
Read next
- Next in Genogram symbolsAdoptionA dashed line down from the parents to a child means the child is adopted. The year of adoption is written beside it, as in A ’97.
- The same shape in African flagsFlag of EthiopiaEthiopia’s flag is green, yellow and red in equal horizontal stripes with a blue disc in the centre holding a yellow star of equal lines with yellow rays. Ethiopia’s Flag Proclamation makes the green labour, fertility and development, the yellow hope, justice and equality, and the red sacrifice and heroism for freedom and equality; the blue disc is peace and the star the unity of Ethiopia’s nations, nationalities and peoples.
More genogram symbols
The same shape elsewhere
Browse symbols drawn with circles, lines or squares and rectangles.
Sources
- QA Case Review: Genogram Resource, ND CFS Quality Assurance, revised November 2022, Children and Family Services Training Center, University of North Dakota, Step 2
- Standard Symbols for Genograms, The Multicultural Family Institute (copy on a PBworks course wiki), Page 1
- GenoGrams, Jay Memmott, Department of Social Work, Washburn University, Basic Symbols, slide 8
- Practice resource-focused revision: Standardized pedigree nomenclature update centered on sex and gender inclusivity: A practice resource of the National Society of Genetic Counselors, Robin L. Bennett, Kathryn Steinhaus French, Robert G. Resta and Jehannine Austin, Journal of Genetic Counseling 31 (2022): 1238–1248, National Society of Genetic Counselors (Wiley), Figure 3, Pedigree line definitions
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 9, 2026. How we research
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