REFERENCE
Pedigree chart symbols
A pedigree is a family tree drawn with a standard notation so any genetics teacher, clinician, or researcher can read it at a glance. This is the same notation PedigreeChartMaker uses — every symbol below is rendered by the editor’s real drawing code.
People
Male
A square represents a man or boy. If clinically relevant, sex assigned at birth is recorded as a separate annotation.
Female
A circle represents a woman or girl. If clinically relevant, sex assigned at birth is recorded as a separate annotation.
Sex unknown
A diamond is used when the sex is unknown, unreported, or intentionally omitted.
Pregnancy
A diamond containing P marks a current pregnancy when fetal sex or gender is unknown or not recorded.
Multiple
A diamond with a number records that many individuals when their details are unavailable; n means the count is unknown.
Affected
A filled (shaded) symbol means the person has the trait. Different traits get different shading or patterns when more than one is tracked.
Carrier
A dot in the center marks a carrier: unaffected but carrying one copy of the allele.
Presymptomatic
A half-filled symbol marks a person who will develop the condition later.
Proband
The person who brought the family to attention; marked with an arrow. The consultand uses an unlabelled arrow.
Deceased
A diagonal slash through the symbol means the person is deceased.
Affected + deceased
Shading and the deceased slash combine.
Relationships and structure
Union (mating) line
A horizontal line connecting two partners. A double line marks a consanguineous union — blood relatives.
Former union
A union that has ended is drawn with a slashed line; both partners still descend from it.
Descent lines
A vertical line from the union line down to the children, who sit below on a horizontal sibling bar.
Twins
Twin branches meet at one point. Monozygotic twins have a connector between the branches; dizygotic twins do not, and unknown zygosity is marked with a question mark.
Adoption
All adoptees use brackets. A dashed descent line connects adoptive parents; a solid line connects biological parents. Bracket direction distinguishes adopted in from adopted out.
Unknown parent
A dashed descent line means the connection is uncertain or the parent is unknown.
Family numbers
Roman numerals (I, II, III…) label generations; pedigree IDs (I-1, I-2, II-3…) give every person a unique reference.
Reading a pedigree: examples and guides
In the autosomal dominant and autosomal recessive template charts you can see the whole notation working together: generations numbered I–III, shading for affected individuals, dots for carriers, and the proband marked with an arrow.
For specialized notation, explore our twins and adoption notation guide, follow the step-by-step pedigree reading walkthrough, or learn how to arrange and export your own chart.