Name: ______

Date: ______Hour: ______

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 here!

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 on the back of the page, 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

Name: ______

Date: ______Hour: _____

Assignment due date: Friday March 18th by the end of the period

Assignment:

You must draw the pedigree chart of this family on the paper provided.

  1. 5 generations must be represented and properly labeled
  2. All information provided must be properly placed on the pedigree chart
  3. Correct symbols for gender must be used
  4. Shaded symbols will indicate an Afflicted (affected) individual. (people who have Huntington’s)
  5. Include marriage lines and birth lines where they apply
  6. The genotype or possible genotypes of each individual must be shown directly below their symbol. (Be careful and do this step last).
  7. Be sure to use pencil

On a separate sheet of paper answer the following questions: (attach this to your pedigree)

  1. Is the trait dominant or recessive?
  1. Does the trait appear to be linked to the sex of the individual or is it a trait carried on an autosome?
  1. How would you propose that this family could get rid of the disease in their family line?
  1. 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: ______/1pts

-Roman numerals

  1. All symbols used correctly: ______/2pts

-squares and circles

-marriage lines properly place

  1. All individuals labeled correctly ______/3pts

-numbering from left to right

-oldest on the left to youngest on the right

-Husbands are always to the left of their wife

  1. Trait identified properly ______/1pts

-shaded symbols indicated afflicted trait

  1. Correct genotypes or possible genotypes are placed under each individual ______/2pts
  1. Neatly presented utilizing the maximum amount of the paper. ______/3pts

-all instructions followed properly

-the pedigree is spaced our evenly utilizing the entire paper

  1. Questions answered: ______/2pts

Final score: _____/14pts