genetics case study: the royal family

Genetics Case Study:Genetics Case Study:The Royal FamilyThe Royal Family

The Romanov FamilyThe Romanov Family•Romanov Empire included one-sixth of the globe.

•Nicholas II became Czar of Russia in 1896

•Resentment against the Czar and wealthy class begins at end of 19th century.

AlexeiAlexei• Born in 1904, Nicholas’s only son.• Had hemophilia, a bleeding disorder.

• Had body guard with him at all times to prevent accidents.

• Alexei had several internal bleeding instances.

• These bleedings were stopped after the prayers of the healer Rasputin.

RasputinRasputin•Healer or Scoundrel????

•Alexandra (Alexei’s mom) called Rasputin in to stop Alexei’s bleeding.

•Alexandra took Rasputin in as a relative (which lowered public faith of the Romanov family). His influence on the Czar is arguable by historians.

•Assassinated by Russian aristocrats.

Rasputin

• Rasputin was drugged, poisoned, and shot before he died of drowning in the Neva river

End of the EmpireEnd of the Empire

•July, 1918: Russian Revolution (Romanov’s assassinated)

•Alexei’s body missing from mass grave found in 1990’s.

So what does this So what does this have to do with have to do with

Genetics?Genetics?Learn how to read a PEDIGREE.Learn how to read a PEDIGREE.

Learn the inheritance pattern of HEMOPHILIA.Learn the inheritance pattern of HEMOPHILIA.

Sex-LinkageSex-Linkage•Traits controlled by genes located on the sex chromosomes are called sex-linked traits.

•The gene for a protein that helps blood clot is on the X chromosome.

•If this gene is mutated (deletion, point mutation, etc), it may cause HEMOPHILIA.

•Heterozygotes are carriers & may pass trait on to children, but themselves appear normal.

•Other sex-linked traits are red-green colorblindness, Duchenne muscular dystrophy, and Fragile X syndrome.

Royal Family Pedigree

Pedigrees

• Each row represents a generation• Genders represented by different

shapes• Affected individuals indicated by

shading• Carriers indicated by half shading

Reading a Pedigree

Sometimes, carriers are indicated this way.

Pedigree Problems: Tips

• Recessive: trait usually skips a generation

• Dominant: trait shows up often

• Autosomal: trait seen in both genders

• Sex-linked: trait seen usually in 1 gender

Sample Pedigrees

Pedigree Practice

Dominant or recessive trait? Autosomal or sex-linked?

Pedigree Practice

Dominant or recessive trait? Autosomal or sex-linked?

Pedigree Practice

Dominant or recessive? Autosomal or Sex-linked?

Practice Problems

• http://www.yhc.edu/external/jasonb/previous_semesters/Bio103_Su2004/Links_of_Interest/links_to_practice_pedigree_probs.htm

Create your own pedigree!

1. Draw your family tree like the pedigrees we’ve seen.

2. Decide on a trait, and shade the affected individuals. (see list of traits on next slide)

3. Show the trait through 3 generations in your family (grandparents, parents, and you and your siblings).

Dominant Recessive

Widow’s peak hairline Straight hairline

Tongue-rolling Can’t roll tongue

Free earlobes Attached earlobes

Can’t bend back 45° Hitchhiker’s thumb

Freckles No freckles

No chin cleft Chin cleft

Bent little finger Not bent

Oval face Square face

Morton’s Toe(2nd toe) Big Toe is tallest

Dark hair (brown/black) Blonde Hair

Not red hair Red Hair