CASE
You are currently assigned to work with pediatric oncology patients. You take a detailed family history of Emily, a 15 year old girl who has a tumor-like growth on her adrenal gland.
Emily has a sister, Lily (age 12), and a brother, Noah (age 8). Both are healthy.
Emily’s mother, Sarah, is a healthy 35 year old.
Emily’s father, David (age 38) is healthy. David doesn’t know the health history of his parents, but isn’t aware of a history of cancer.
Sarah is the youngest of four. Her eldest brother, Mark (age 43) has no signs or symptoms of cancer. Her sister, Anna (age 40) has bilateral breast cancer. They had a brother, James, who died of leukemia at age 10. He was the third child of Sarah’s parents.
Mark’s two daughters have no signs or symptoms of cancer. They have the same mother who also does not have signs of cancer.
Sarah’s father, John, died of a soft tissue sarcoma at age 42.
Sarah’s mother, Mary, is still living and in excellent health.
John’s mother died of a brain tumor at age 30. John was her only child.
Draw the pedigree for this family. Make sure to use proper symbols and notation to indicate the proband, label each generation and individual within each generation. You do not need to add year of birth but add ages. You do NOT need to indicate carriers.
You can draw it out and take a picture, write your name and the date on your paper when you take a picture for authentication.
This assignment is worth 7% of your final grade. Due on Sunday, Oct 20 at 11:59 PM. Late assignments will be penalized 10% per day until Wed, Oct 23 at 11:59 PM then assignments will no longer be accepted.
There is a pattern to this family inheritance of cancer. Use the table to help organize your thoughts and to propose a possible genetic mechanism. Supply a brief rationale as to why or why not that proposed genetic mechanism makes sense with the pedigree evidence. I filled out one as an example. It may be possible that more than one mode of inheritance is justified. You only need to provide one rationale per mechanism.
Mode of Inheritance Possible Possible but not likely Not possible Rationale
Spontaneous (not inherited)
Autosomal Recessive
Autosomal Dominant
X-linked recessive
X-linked dominant
Y-linked x Women are affected
Here are some Faqs about the assignment. I’ll update these as needed.
For the purposes of this assignment, lets use the rule of thumb to include parents for any NAMED individuals.
For the mother of Mark’s daughters, lets assume that both daughters have the same mother and that she is healthy. She is un-named.
Do I need to include the names and ages of the family members within the pedigree?
Only generation and individual number are required; however, adding names is very helpful to me for grading (but no points will be deducted if you don’t)
Do I need to draw out a separate pedigree to fit each mode of inheritance?
no – one pedigree only.
Do I need to write out a brief rationale in addition to completing the table?
The rationale is embedded within your table. Write in the 5th column one short piece of evidence or observation that helped you decide how possible the mode of inheritance was. Remember the example I already entered “women are affected” to rule out Y-linked disorder. That was 3 words. That’s fine.