Genetics Case Study: The Royal Family

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Genetics Case StudyThe Royal Family
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The 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.

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Alexei

• Born in 1904, Nicholass 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.

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Rasputin

• Healer or Scoundrel????
• Alexandra (Alexeis mom) called Rasputin in to
  stop Alexeis 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.

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Rasputin

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

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End of the Empire

• July, 1918 Russian Revolution (Romanovs
  assassinated)
• Alexeis body missing from mass grave found in
  1990s.

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So what does this have to do with Genetics?
Learn how to read a PEDIGREE. Learn the
inheritance pattern of HEMOPHILIA.
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Sex-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.

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Royal Family Pedigree
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Pedigrees

• Each row represents a generation
• Genders represented by different shapes
• Affected individuals indicated by shading
• Carriers indicated by half shading

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Reading a Pedigree
Sometimes, carriers are indicated this way.
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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

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Sample Pedigrees
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Pedigree Practice
Dominant or recessive trait? Autosomal or
sex-linked?
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Pedigree Practice
Dominant or recessive trait? Autosomal or
sex-linked?
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Pedigree Practice
Dominant or recessive? Autosomal or Sex-linked?
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Practice Problems

• http//www.yhc.edu/external/jasonb/previous_semest
  ers/Bio103_Su2004/Links_of_Interest/links_to_pract
  ice_pedigree_probs.htm

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Create your own pedigree!

1. Draw your family tree like the pedigrees weve
   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).

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Dominant Recessive
Widows peak hairline Straight hairline
Tongue-rolling Cant roll tongue
Free earlobes Attached earlobes
Cant bend back 45 Hitchhikers thumb
Freckles No freckles
No chin cleft Chin cleft
Bent little finger Not bent
Oval face Square face
Mortons Toe(2nd toe) Big Toe is tallest
Dark hair (brown/black) Blonde Hair
Not red hair Red Hair