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Pedigree charts, explained
Guides on reading and drawing pedigree charts, the inheritance patterns that show up in them, and practical tips for classrooms and families.
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Basics
Pedigree Chart vs Genogram: What's the Difference?
Pedigrees and genograms look alike but answer different questions. Compare their notation, audience, and purpose — and when to use which.
Read →How to Read a Genetics Pedigree Chart, Step by Step
A practical walkthrough of reading a pedigree chart: find the proband, identify the pattern, check sexes and carriers, and decide on the likely mode of inheritance.
Read →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.
Read →Notation
Twins and Adoption in Pedigree Charts: The Special Marks
How to draw and read twins (monozygotic vs dizygotic) and adoption (adopted-in vs adopted-out) on a pedigree, with the standard bars and brackets explained.
Read →Pedigree Symbols and Notation, Fully Explained
Every pedigree symbol decoded: squares, circles, diamonds, shading, carrier dots, proband arrows, deceased slashes, twin bars, consanguineous double lines, and adoption brackets.
Read →Inheritance patterns
Y-Linked and Sex-Limited Traits: The Patterns Most Textbooks Skip
Beyond X-linked: what Y-linked inheritance looks like on a pedigree, why it's rare, and how sex-limited and sex-influenced traits differ from sex-linked ones.
Read →Mitochondrial Inheritance on a Pedigree: Mother's Line Only
How mitochondrial inheritance shows up on pedigree charts: all children of an affected mother affected, fathers never transmit, and why the pattern looks like a maternal column.
Read →X-Linked Recessive Pedigrees: The Patterns That Give Them Away
How X-linked recessive inheritance appears on a pedigree: mostly affected males, carrier mothers, and no father-to-son transmission — with the visual cues to spot it.
Read →Autosomal Dominant vs Autosomal Recessive: Reading the Pedigree
How to tell autosomal dominant from autosomal recessive inheritance on a pedigree chart — with the visual cues to look for in each generation.
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