Question

1 Using your knowledge of X-linked inheritance, explain why males are more vulnerable than females to miscarriage, infant death, genetic disorders, and other problems.

2. Suppose you are a carrier of fragile X syndrome and want to have children. Would you choose pregnancy, adoption, or surrogacy? If you became pregnant, would you opt for prenatal diagnosis? Explain your decisions.

Answer 1

1. explain why males are more vulnerable than females to miscarriage, infant death, genetic disorders, and other problems.

X linked inheritance are recessive and cause recessive conditions. This implies that when females contain x linked carrier gene, both the genes should be containing the mutant or the mutation. Whereas, when the males contain the defective gene, one copy of gene, X and Y, would contain the mutation. Males, containing the mutation in the single gene, would be an affected person, since males only contain one X chromosome, and that one chromosome is also affected. Hence, x linked diseases are more common in the males, and not females.

2. Suppose you are a carrier of fragile X syndrome and want to have children. Would you choose pregnancy, adoption, or surrogacy? If you became pregnant, would you opt for prenatal diagnosis? Explain your decisions.

A woman who is having a fragile x carrier, and if this gene is passed on to the child, then, the child may also be having the risk of having the fragile x syndrome. The risk of the child for having the fragile x syndrome, would depend on the CCG repeats number that is present on the carrier and on the number of interruptions on AGG, are present on the carrier. It is also shown that AGG interruptions stabilise the gene, as a result, making it less likely that the mother would have an affected child. Thus, before getting pregnant, the mother should perform AGG testing.