Parents who both have "sickle-cell trait", i.e, are heterozygous for HbS have a child who is tested at birth, and is found to be homozygous for HbS (both alleles affected). What is the molecular reason why the child presents with no symptoms until 6 months of age? a.) the mutation affects the beta chain, which is not dominant at birth b.) the mutation affects the alpha chain, which is not dominant at birth c.) babies cannot be exposed to low oxygen that triggers symptoms d.) babies cannot be exposed to high oxygen that triggers symptoms
Parents who both have "sickle-cell trait", i.e, are heterozygous for HbS have a child who is tested at birth, and is found to be homozygous for HbS (both alleles affected). What is the molecular reason why the child presents with no symptoms until 6 months of age?
Sickle cell anemia is a blood disorder in which a mutation in one the hemoglobin genes causes the production of abnormal hemoglobin protein. As a result, the shape of red blood cells (that carry hemoglobin) changes from the normal biconcave to an abnormal sickle-like one.
Because of the deformed shape, the ability of hemoglobin to carry oxygen to tissues decreases. Low concentration of normal hemoglobin and red blood cells also results in anemia.
It is an autosomal recessive disorder, i.e., both alleles for that gene must be mutated in order for the person to have the disease. It can be inherited by an individual if both their parents are carriers (heterozygous).
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
