Final answer:
Each daughter has a 50% chance of being a premutation carrier and a 25% chance of having have the full mutation.
Craig's daughters each have a 50% chance of being premutation carriers of the FMR1 gene mutation, but the risk of them having a full mutation is minimal to none.
Step-by-step explanation:
Since Craig is a premutation carrier with a repeat length of 99 on his FMR1 gene, each of his daughters has a 50% chance of also being a premutation carrier. As for having the full mutation, the chance is 25%. This means that each daughter has a 50% chance of being a carrier like their father, and a 25% chance of having the full mutation.
Craig's daughters each have a 50% chance of being premutation carriers of the FMR1 gene mutation, but the risk of them having a full mutation is minimal to none.
Craig, a premutation carrier with a repeat length on his FMR1 gene of 99, can pass on the fragile X syndrome mutation to his offspring. When it comes to genetic inheritance, especially with X-linked conditions such as the fragile X syndrome, each daughter has a 50% chance of being a premutation carrier because they will receive one X chromosome from their father and the status of that chromosome (whether it's a pre-mutation or full mutation) remains the same. However, because the full mutation generally occurs when the number of repeats increases significantly in the next generation, particularly during transmission from a female who has more than one X chromosome, the daughters do not have an increased risk of having the full mutation, but rather maintain the same premutation risk. Therefore, each of Craig's daughters has a 50% chance of being a premutation carrier and a minimal to no chance of having the full mutation, since full mutations typically arise during transmission from a female.