NAME:___________________________
Pedigree Activity: Wexler’s Search for the Huntington’s Gene
The year was 1979, and Congress has just issued you the funding to study Huntington’s disease – a disorder afflicting more than 50,000
Americans. Very little was known about the inheritance of Huntington’s but Dr. Nancy Wexler (who’s mother died of it) knew about the
incredibly high rate of the disease around a place called Maracaibo, Venezuela. Here, you’ll be a part of a team sent to Lake Maracaibo to
study a large family (of more than 5, 000 members) and report your findings. The family spans five generation. It is your job (as it was hers)
to pedigree the family and see what’s going on! Below is a fax from the team at Lake Maracaibo…..
To: Genetic Research Team, Grosse Pointe South High School
From: Huntington’s Research Team, Lake Maracaibo
Dear Scientists,
What follows are the results of our interviews with 36 members of the Gonzales family. See what you can make of it.
Sincerely,
The Team
Generation I:
Rigo – AFFLICTED
Esmeralda – HEALTHY
Generation II:
Rigo and Esmeralda’s children
Daughter Imelda – AFFLICTED, married to Carlos – HEALTHY
Son Javier – AFFLICTED, married to Bonita – HEALTHY
Son Chito – AFFLICTED, married to Chelita – HEALTHY
Generation III:
Imelda & Carlos’ children
Daughter Lydia – AFFLICTED, married to Ricardo – HEALTHY
Daughter Helga – HEALTHY, not married
Daughter Letty – AFFLICTED, married to Miguel – HEALTHY
Daughter Margarita – AFFLICTED, married to Jose – HEALTHY
Daughter Beatriz – AFFLICTED, married to Pedro – HEALTHY
Javier & Bonita’s children:
Daughter Juanita – AFFLICTED, not married
Son Benito – HEALTHY, not married
Chito & Chelita’s children:
Son Dano – AFFLICTED, married to Andrea – HEALTHY
Son David – AFFLICTED, married to Guadalupe – HEALTHY
Son Horatio – HEALTHY, not married
Son Lucio – HEALTHY, not married
Generation IV:
Ricardo & Lydia’s children
Son Ramon – AFFLICTED, married to Zelda – HEALTHY
Son Felipe – AFFLICTED, not married
Miguel & Letty’s children
Son Juan – AFFLICTED, not married
Daughter Cira – HEALTHY, not married
Son Roberto – HEALTHY, not married
Jose & Margarita’s children
Daughter Nora – AFFLICTED, not married
Pedro & Beatriz’s children
Son Alejandro – AFFLCITED, not married
Dano & Andrea’s children
Daughter Delia – AFFLICTED, not married
Son Tio – AFFLICTED, not married
Generation V:
Zelda & Ramon’s children
Son Luis – AFFLICTED, not married
Assignment:
Assignment due date: ____________________
You must draw the pedigree chart of this family on the paper provided.
a. 5 generations must be represented and properly labeled
b. All information provided must be properly placed on the pedigree chart
c. Correct symbols for gender must be used
d. Shaded symbols will indicate an Afflicted (affected) individual.
e. Include marriage lines and birth lines where they apply
f. The genotype OR possible genotypes of each individual must be shown directly below their symbol. (Be careful
and do this step last).
g. Be sure to use pencil
On the back of your pedigree answer the following questions:
1.
Is the trait dominant or recessive?
2.
Does the trait appear to be linked to the sex of the individual or is it a trait carried on an autosome?
3.
How would you propose that this family could get rid of the disease in their family line?
4.
Genetic testing is available for people to determine if they carry the gene for Huntington’s disease. Should this family all be
tested before they decide to have children? Why or Why not?
You will be graded on the following:
1.
All generations present and labeled correctly:
-Roman numerals
______/2pts
2.
All symbols used correctly:
-squares and circles
-marriage lines properly place
______/2pts
3.
All individuals labeled correctly
-numbering from left to right
-oldest on the left to youngest on the right
-Husbands are always to the left of their wife
______/3pts
4.
Trait identified properly (recessive and dominant)
-shaded symbols indicated afflicted trait
______/2pts
5.
Neatly presented utilizing the maximum amount of the paper.
-all instructions followed properly
-the pedigree is spaced our evenly utilizing the entire paper
______/4pts
6.
Questions answered:
______/2pts
Final score:
______/15pts