Question 1

John, a 27-year-old white male, with a PMHx of familial adenomatous polyposis (FAP) comes to the clinic because him and his wife are thinking about having children. He is concerned about passing FAP to his children because he knows that there is 50% chance of passing the condition to each of his children. He states that he had his colectomy when he was 16-years-old. What is true regarding the condition?

A) He cannot pass FAP to his children since he had his colon removed.
B) Since he had a colectomy, his chance of passing on FAP to his children reduced to 25%.
C) Since he had a colectomy, his chance of passing on FAP to his children increased to 75%
D) Even with a colectomy, he still has a 50% chance of passing FAP to each of his children.

D
Explanation: Individuals with FAP have a 50% chance of passing the condition to each of their children, even if the patient has had their own colon removed, and FAP can be passed on to offspring even after a colectomy.

Accepted Answer

Individuals with FAP have a 50% chance of passing the condition to each of their children, even if the patient has had their own colon removed, and FAP can be passed on to offspring even after a colectomy.

Question 2

A 26-year-old woman who was recently diagnosed with Hereditary Nonpolyposis Colorectal Cancer presents to the clinic worried about consequences of having this condition. What two types of cancers is she highest at risk for with HNCCP?

A) Colorectal cancer and endometrial cancer
B) Small bowel cancer and stomach cancer
C) Stomach cancer and bile duct cancer
D) Colorectal cancer and ovarian cancer

Accepted Answer

Hematochezia, blood in the stool, is a symptom of colorectal cancer that the patient should be cautious about. Persistent decrease in the size and caliber of stool is a sign associated with colorectal cancer, not increase in the size of caliber of stool. Diarrhea that is not the result of diet or illness is a sign associated with colorectal cancer. Weight loss is a sign associated with colorectal cancer, not weight gain.

Question 3

Mutation in what genes causes familial adenomatous polyposis (FAP) and variant of familial adenomatous polyposis?&#10;A) APC and MYH&#10;B) MLH1 and MSH2&#10;C) PMS2 and APC&#10;D) MSH6 and MYH

Accepted Answer

FAP is an autosomal dominant condition caused by mutations in the APC tumor suppressor gene. Additionally, an autosomal recessive CRC syndrome, MUTYH-associated polyposis (MAP), a variant of FAP, has also been identified as another hereditary CRC. MLH1 and MSH2 mutations cause HNPCC, not FAP. A defect in one of several genes (MLH1, MSH2, MSH6, and PMS2) that are important in the detection and repair of DNA base-pair mismatches causes HNPCC.

Question 4

An 18-year-old female presented with a positive HNPCC gene mutation who had relative that was diagnosed with HNPCC at the age of 30, 32 and 45. At what age should she start getting screened and with what test?

A) At the age of 30, with a colonoscopy
B) At the age of 25, with a sigmoidoscopy
C) At the age of 25, with a colonoscopy
D) At the age of 30, with a sigmoidoscopy

Accepted Answer

With a documented MMR gene mutation, affected relatives should be screened with colonoscopy every 1 to 2 years beginning at age 25 or at an age 5-10 years younger than the age at diagnosis of the youngest affected family member, whichever is first. Since this patient's youngest relative was diagnosed with HNPCC at the age of 30, she should start receiving screening at the age of 25. As stated earlier, these screenings should be done with a colonoscopy.

Question 5

A 20-year-old male is diagnosed with FAP, what is the next recommendation?&#10;A) Complete proctocolectomy or colectomy&#10;B) Partial proctocolectomy or colectomy&#10;C) Complete proctectomy&#10;D) Partial proctectomy

Accepted Answer

Once FAP has been diagnosed, complete proctocolectomy or colectomy is recommended before the age of 20.

Question 6

In what hereditary pattern is lynch syndrome most commonly inherited?&#10;A) Autosomal recessive&#10;B) X-linked inheritance&#10;C) Autosomal dominant&#10;D) Y-linked inheritance

Accepted Answer

Lynch syndrome is an autosomal dominant condition that dramatically increases risk of many kinds of cancer, most commonly CRC.

Question 7

Men and women at average risk for colorectal cancer should start getting screened at what age?&#10;A) Age 45&#10;B) Age 50&#10;C) Age 60&#10;D) Age 55

Accepted Answer

Individuals with average risk for developing colorectal cancer should take the screening tests at the age of 50.

Question 8

Lynch syndrome occurs as a result of defect in one or several genes that are important in detection and repair of DNA base-pair mismatches. What is the phenotypic abnormality that results as a mutation in an allele of a mismatch repair (MMR) gene?

A) Chromosomal instability
B) Nucleotide instability
C) Macrosatellite instability
D) Microsatellite instability

Accepted Answer

The characteristic phenotypic DNA abnormality that results as a mutation in an allele of a mismatch repair (MMR) gene is microsatellite instability.

Question 9

At what age should an individual with a family history of attenuated FAP begin getting screened for FAP? When should the screening be repeated?&#10;A) At age of 20 and repeated 1-3 years&#10;B) At age of 15 and repeated 1-3 years&#10;C) At age of 15 and repeated 5-7 years&#10;D) At age of 20 and repeated 5-7 years

Accepted Answer

Individuals with a family history of attenuated FAP should begin getting screened for FAP at the age of 15 and it should be repeated every 1-3 years. This is because in a family with attenuated FAP, number of polyps and age of onset can vary greatly from one family member to another, so it is best to start screening early and repeat it frequent.

Deck 8: Colorectal Cancer