In: Biology
5. If 1/1000 individuals with your genetic background are carriers for a certain autosomal, recessive disease allele, what is the chance that both you and your spouse will be carriers?
6. (Related to 5) What is the chance that you will both be carriers and have an affected child?
7. (Related to 5 and 6) If you are a carrier for this disease allele and your spouse’s status is unknown, what is you chance of having a child with the disease?
Answer:
5. If 1/1000 individuals with your genetic background are carriers for a certain autosomal, recessive disease allele, what is the chance that both you and your spouse will be carriers?
6. (Related to 5) What is the chance that you will both be carriers and have an affected child?
7. (Related to 5 and 6) If you are a carrier for this disease allele and your spouse’s status is unknown, what is you chance of having a child with the disease?
This will be a combination of two cases:
a) Both husband and wife are carrier
Chance of having a child with the disease (1 in 4) = 0.25*10.-6 = 2.5*10-7
b) Husband is carrier and wife is affected (2 in 4) = 0.50*10.-6 = 5.0*10-7
c) Husband is carrier and wife is not affected = 0
Probability = 2.5*10-7 + 5.0*10-7 = 7.5 *10-7