What mutation is often screened for when diagnosing sickle cell disease?

The mutation commonly screened for when diagnosing sickle cell disease is the HBB gene mutation that leads to the production of abnormal hemoglobin known as hemoglobin S (HbS). Sickle cell disease is primarily caused by a single nucleotide substitution in the HBB gene on chromosome 11, where thymine (T) is replaced by adenine (A) at the sixth codon of the beta-globin gene. This specific change alters the amino acid sequence, substituting valine for glutamic acid, which is the underlying cause for the sickle shape of red blood cells under low oxygen conditions.

This screening is critical because identifying individuals with this mutation enables better management of the disease, including preventive care and family planning options. In contrast, the other options refer to different mutations and genetic conditions not relevant to sickle cell disease diagnosis. For example, the BRCA1 AJ founder mutation pertains to breast and ovarian cancer risk and is not associated with hemoglobin disorders. Thus, for accurate diagnosis and tracing of sickle cell disease, the HBB gene screening is essential.