Cnaiienge Probiem: What is the likellhood that this individual inherited at leas

Question

Cnaiienge Probiem: What is the likellhood that this individual inherited at least one non-functional allele, predisposing him to cancer? Assume that every individual in thi spedigree that died of cancer was heterozygous with respect to a cancer-supressor gene Individual died from other cause Individual died from colon cancer Living individual Note: To make calculating the probability more manageable, assume that every person who died of cancer in this pedigree was genetically predisposed to cancer. Also, cancer is a complex condition, resulting from malfunctioning of many proteins encoded for by many genes. For this problem, however, you may treat this condition as though this is a single-gene trait. Also, even though you technically dont know whether a person who died of another cause was not predisposed to cancer or not, for this problem, please assume that these individuals are NOT predisposed to cancer KEEP IN MIND THAT AN INDIVIDUAL CANNOT LIVE IF THEY ARE HOMOZYGOUS RECESSIVE This question is a challengel It requires careful use of both the AND and the OR rules of calculating probabilities. This problem is far harder than anything you will see on your quiz or hour exam. In the space below, write your answer of the probability that this individual inherited 1 non-functional allele of the cancer-suppressor gene predisposing him to cancer, but remembering that no individual that survives to birth can be homozygous for the recessive non-functional allele. READ THIS IF YOU WANT MOODLE TO GIVE YOU CREDIT eK Write your probability as a decimal fraction, starting with 0. and including 4 decimal places

Explanation / Answer

The given pedigree shows an autosomal recessive disorder.

Reasons:

i. Both sexes are equally affected.

ii. Disease condition is seen only in homozygous condition.

WT dominant allele = A

Mutant recessive allele = a

A person can show WT phenotype in AA or Aa condition.

A person has to be aa to exhibit mutant phenotype.

II-3 = aa

II-4 = Aa

Parental cross of II-3 X II-4 = aa X Aa

Progeny: Aa aa Aa aa

The probability that the person can be affected = 2/4 = 1/2 = 0.5 = 50%

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.