A pedigree is a chart of the genetic history of several generations in a family. Scientists or genetic counselors will find out your family history and make this chart for analysis.
One important tool geneticists is the Pedigree Chart, which you can use to track genetic traits across generations of a family, for example. It’s a family history and details about previous generations that can become inconclusive as memories fade.
Elements of Pedigree chart
Pedigrees use a standardized set of symbols
- Squares Represent Males
- Circles Represent Females.
- If The Sex Of The Person Is Unknown A Diamond Is Used. Someone With The Phenotype In Question Is Represented By A Filled-In (Darker) Symbol.
- Heterozygotes, When Identifiable, Are Indicated By A Shaded Dot Inside A Symbol Or A Half-Filled Symbol.
- Relationships In A Pedigree Are Shown As A Series Of Lines.
- Parents Are Connected By A Horizontal Line And A Vertical Line Leads To Their Offspring.
- The Offspring Are Connected By A Horizontal Sibship Line And Listed In Birth Order From Left To Right.
- If The Offspring Are Twins Then They Will Be Connected By A Triangle. If An Offspring Dies Then Its Symbol Will Be Crossed By A Line.
- If The Offspring Is Stillborn Or Aborted It Is Represented By A Small Triangle.