Question

Sandra has sickle cell anemia, a recessive blood disorder caused by an inability to make an effective hemoglobin protein. Sandra volunteered for a gene therapy trial. After gene therapy Sandra has no more symptoms of Sickle cell anemia. Does she still risk passing on the mutant allele to her children?

a) Yes, because gene therapy does not affect germline cells
b) No, because gene therapy corrects all genetic abnormalities
c) Yes, because the gene therapy only addresses symptoms
d) No, because gene therapy modifies germline cells

Answer 1

Even though gene therapy alleviated Sandra's symptoms of sickle cell anemia, she can still pass on the mutant allele to her children because gene therapy does not change her germline cells.

Step-by-step explanation:

Sickle cell anemia is an autosomal recessive disorder caused by a single base change in the gene for human β-hemoglobin, affecting the shape and function of red blood cells. Gene therapy can correct the dysfunctional gene in somatic (body) cells, alleviating symptoms of the disease, as seen in Sandra's case.

However, this therapeutic intervention does not typically alter germline cells, which are the cells that contribute genetic information to offspring. Therefore, people who have undergone gene therapy for sickle cell anemia can still be carriers of the mutation and risk passing the mutant allele to their children.

The distinction between somatic and germline cell modification is crucial in gene therapy. Current gene therapy practices generally do not target reproductive cells. Thus, while Sandra no longer shows symptoms after treatment, the underlying genetic mutation remains in her germline cells, posing a risk for her potential children to inherit the disorder if the other parent also carries the allele.