Transcript Genetics Case Study: The Royal Family

Genetics Case Study:
The Royal Family
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.
Alexei
• 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.
Rasputin
•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 Empire
•July, 1918:
Russian Revolution
(Romanov’s
assassinated)
•Alexei’s body
missing from mass
grave found in
1990’s.
So what does this
have to do with
Genetics?
Learn how to read a PEDIGREE.
Learn the inheritance pattern of HEMOPHILIA.
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.
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/previou
s_semesters/Bio103_Su2004/Links_of_Inte
rest/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
Widow’s peak hairline
Tongue-rolling
Free earlobes
Can’t bend back 45°
Freckles
No chin cleft
Bent little finger
Oval face
Morton’s Toe(2nd toe)
Dark hair (brown/black)
Not red hair
Recessive
Straight hairline
Can’t roll tongue
Attached earlobes
Hitchhiker’s thumb
No freckles
Chin cleft
Not bent
Square face
Big Toe is tallest
Blonde Hair
Red Hair