Before the computation of the probability of the genotypes of John and Sue, the pedigree should be completed first as much as possible. It should be noted that John's father and Sue's mother are both carriers of the disease as they are definite recipients of the recessive allele from their affected parents. Additionally, John's first sister (III-1) is also known to have been affected. And since this disease is autosomal recessive, at least both parents should be carriers for it to be expressed in their children. The pedigree can be seen below.
John and Sue are expecting a child, but are concerned about a rare autosomal recessive disease that is present in both of their families. In the pedigree below, John is represented as individual III-11 and Sue is represented as individual III-12. John's sister, III-10, and Sue's brother, III-13, both do not show evidence of the disease, but John's paternal grandmother and Sue's maternal grandfather both had the disease.
What is the probability that John is a carrier?
What is the probability that both John and Sue are carriers?
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Genetic Counseling concept. You can view video lessons to learn Genetic Counseling. Or if you need more Genetic Counseling practice, you can also practice Genetic Counseling practice problems.
What professor is this problem relevant for?
Based on our data, we think this problem is relevant for Professor Herrick's class at UCONN.