Question

(a) Using Bayes Analysis, calculate the posterior probability that Theo (from Q3) is a carrier for Thalassemia.

(b) Using the risk figure calculated in (a), calculate the probability that Theo and Martina’s third child is healthy.

Q3. Thalassemia is an autosomal recessive condition, particularly prevalent in African and Mediterranean countries. Theo's brother has Thalassemia and Theo's wife Martina is a known carrier for Thalassemia. Theo and Martina have two healthy children, Eva and Thomas Draw a pedigree, showing all available information. Insert your image into the pdf form as a JPEG. Q4. (a) Using Bayes Analysis, calculate the posterior probability that Theo (from Q3) is a carrier for Thalassemia Scenario A Theo is a carrier Scenario B Theo is not a carrier Prior Probability Cond. Probability Joint probability Posterior probability (b) Using the risk figure calculated in (a), calculate the probability that Theo and Martina's third child is healthy. The probability that Theo and Martina's third child is healthy

Answer 1

Probability	Theo is carrier p(C)	Theo is not carrier p(NC)
Prior	1/2	1/2
Cond.	1	1
Joint	1/2	1/2
Posterior	1/2	1/2

Prior probability is chance of acquiring the defective gene which is 1/2

Cond probability is chance of being a career when gene is inherited 1

Joint prior* cond= 1/2

Posterior = joint for occurance/ joint for occurance+ joint for no occurance

= 1/2

Probability that Theo and Martina's third child is healthy is 1/2