What Is a Pedigree Chart? A Beginner's Guide
A pedigree chart is a family tree drawn with standard symbols to show relationships and inherited traits. Learn what the shapes mean and why they matter in genetics.
- basics
- notation
- genetics-education
A pedigree chart is a family tree drawn with a standardized set of symbols. Where a regular family tree focuses on names and dates, a pedigree chart adds health information: who has a condition, who carries it, and how it travels through the generations.
If you’ve seen one in a genetics textbook, a genetics clinic, or a dog breeding program, you’ve seen the same visual language — squares, circles, lines, and shading. That consistency is the point: anyone trained in the notation can read any pedigree, regardless of who drew it.
What a pedigree chart shows
Three kinds of information:
- Relationships — who is a parent, partner, sibling, or twin of whom.
- Sex — squares for males, circles for females, diamonds for unknown.
- Trait status — who is affected, a carrier, presymptomatic, or deceased, plus the proband (the person who brought the family to attention).
How to read one quickly
Read a pedigree top to bottom: older generations on top, younger below. A horizontal line connects two partners; a vertical line drops from their union to their children. Children are drawn left to right in birth order.
Shading is the most important habit to pick up. Fill = affected. A dot in the middle = unaffected carrier. A diagonal slash = deceased. An arrow = proband.
Why they matter
- In genetics education, pedigrees teach students how to recognize inheritance patterns.
- In clinics, a family health history drawn as a pedigree helps counselors spot risk patterns fast.
- In family research, pedigrees organize several generations of relatives and conditions in one printable page.
Making your own
You don’t need to draw boxes and lines by hand. Tools like PedigreeChartMaker handle the notation — you add people, mark their status, and the chart renders with standard symbols. Start from a blank page or a template of the inheritance pattern you’re studying, then export a print-ready PNG, SVG, or PDF.
Quick start: open the chart maker, pick a template, add a few relatives, and shade someone as affected. You’ll understand more in five minutes than from a page of theory.
For the full symbol set, see the pedigree symbols guide.