Question

If a couple with the genotypes FfEeWwHhDd and FfEeWwHhDd has children, what is the chance the children will inherit the following characteristics?

Day06-PedigreesProbabilities,Webic.pdf Q. 匕 Calculating Probabilities in Pedigrees →An example-if the condition shown is a rare autosomalrecessíve. what is the probability that the first child of IV-4 and IV-5 will be affected? 다 -O Mike Sally

Answer 1

an autosomal recessive disease is whrn two copies of an abnormal gene must be present in order for the disease to be seen. so if the parwnts are not affected they must be heterozygous.

for the first child born to a couple who both carry the gene (but do not have signs of disease), the expected outcome for each pregnancy is:

• A 25% chance that the child is born with two normal genes (normal)
• A 50% chance that the child is born with one normal and one abnormal gene (carrier, without disease)
• A 25% chance that the child is born with two abnormal genes (at risk for the disease)