Question

Huntington’s disease and sickle cell anemia are both hereditary gene mutations. Huntington’s disease is eventually fatal because it causes a breakdown of the nervous tissue in the brain. Sickle cell anemia is a mutation that causes an alteration in the shape of red blood cells, which affect delivery of oxygen to the body. Review the images, and then answer the questions.

a diagram showing the inheritance pattern and mutated gene structure in Huntington's disease

a diagram showing the inheritance pattern and mutated gene structure in sickle cell anemia

Part A
Based on the pattern of inheritance, do you think the mutated Huntington’s and sickle cell genes are dominant or recessive?

Answer 1

Based on the pattern of inheritance, the mutated Huntington's gene is dominant and the mutated sickle cell gene is recessive.

Huntington's Disease:

Huntington's disease is an autosomal dominant genetic disorder. This means that a person only needs one copy of the mutated gene to develop the disease. The other copy of the gene can be normal.

Sickle Cell Anemia:

Sickle cell anemia is an autosomal recessive genetic disorder. This means that a person needs two copies of the mutated gene to develop the disease. If a person only has one copy of the mutated gene, they are a carrier of the disease, but they do not have the disease themselves.