1. Fun with Pedigrees
Mr. Arndt | November 10, 2016

2. Genetics in Humans
We have more knowledge about humans than any other organism for anatomy, physiology, and biochemistry
Detailed genealogy and record keeping
BUT:
Controlled matings seemingly impossible (no testcrosses)
Long generation times
Family size is small, so probabilities affected by chance
So how do we study inheritance of genetic traits in humans? Pedigrees!

3. Key

4. Key

5. General rules
Each generation in a pedigree is identified by a Roman numeral
Family members numbered in each generation from left to right
Filled in symbols are afflicted with the trait
Sometimes, half-filled are carriers
Children listed in birth order

6. Autosomal Recessive traits
Appear with equal frequency in both sexes
Need two recessive alleles
Skips generations

7. Autosomal Dominant Present in both sexes equally
Do not skip generations, unless new mutation
Example: familial hypercholesterolemia

8. X-linked recessive More frequent in males than females
Skips generations (unaffected mother to affected son)
Example: hemophilia

9. X-linked dominant More frequent in females than males
Do not skip generations
Males inherit only from mother, both females can inherit dominant allele from both parents

10. Y-linked
Only males
Father to son