1. Pedigree Charts

2. Pedigree
The recorded ancestor of an individual

3. Pedigrees and Animals
Can be used to track animal breeding and enhance desirable traits through selective breeding
(i.e. Dog breeds, horses, etc.)

4. Studying human genetics
You cannot make humans of different types breed together
Pedigree charts offer an ethical way of studying human genetics

5. Studying human genetics
Today genetic engineering has new tools to offer doctors studying genetic diseases
A genetic counsellor will still use pedigree charts to help determine the distribution of a disease in an affected family

6. Studying human genetics
Pedigrees can be used to study the transmission of a genetic condition in a family
Can help predict the likelihood that a child will inherit a genetic disorder

7. Studying human genetics
Can diagnose whether a genetic condition as dominant or recessive
Can help parents make decision about having children (family planning)

8. Symbols used in pedigree charts
A marriage with five children, two daughters and three sons. The eldest son is affected by the condition.
Eldest child  Youngest child
Normal male
Affected male
Normal female
Affected female
Marriage
© 2007 Paul Billiet ODWS

9. Organizing the pedigree chart
A pedigree chart of a family showing 20 individuals
© 2007 Paul Billiet ODWS

10. Organizing the pedigree chart
Generations are identified by Roman numerals I II
III IV
© 2007 Paul Billiet ODWS

11. Organizing the pedigree chart
Individuals in each generation are identified by Arabic numerals numbered from the left
Therefore the affected individuals are II3, IV2 and IV3 I II
III IV
© 2007 Paul Billiet ODWS

12. What type of disorder is this?

13. Autosomal Recessive Disorders
In an autosomal recessive disorder individuals can inherit the condition even if neither of their parents are affected
The condition can “skip” a generation

14. What type of disorder is this? Autosomal Recessive

15. What type of disorder is this?

16. Autosomal Dominant Disorder
Individuals only inherit the disorder when a parent is affected
The disorder will not “skip a generation”
In most families, the children have a 50% probability of having the disorder.

17. What type of disorder is this? Autosomal Dominant