What is B-HbS (hemoglobin S)?
B-HbS is an analysis used to detect the presence of hemoglobin S (HbS), a genetic variant of hemoglobin. HbS is produced due to a change in the gene encoding beta-globin and is the hemoglobin variant associated with sickle cell disease.
In individuals without the HbS variant, the result may be reported as HbS not detected. If HbS is identified, the result must be interpreted together with other hemoglobin fractions to determine whether it indicates sickle cell trait or a sickle cell disorder.
Why is HbS analyzed?
HbS analysis is primarily used to identify genetic changes affecting hemoglobin and is an important part of the investigation of:
Sickle cell anemia and other forms of sickle cell disease
Sickle cell trait (HbAS), where an individual carries one HbS gene
HbSC disease, a combination of two different hemoglobin variants
Sickle cell beta-thalassemia
The presence of HbS does not always mean that a person has a disease. In carriers, both normal hemoglobin (HbA) and HbS are usually present, while individuals with sickle cell disease may have a different pattern of hemoglobin fractions.
Part of the Hemoglobin Fractions analysis
HbS is often analyzed together with other hemoglobin fractions such as HbA, HbA2, and HbF. The combination of these results provides an overall picture of the hemoglobin types present in the blood.
The analysis is used to detect abnormal hemoglobins and support the diagnosis of various hemoglobinopathies.
When may HbS analysis be considered?
Testing for HbS may be considered in cases of:
Suspected sickle cell trait or sickle cell disease
Abnormal findings in blood count or hemoglobin analysis
Investigation of inherited blood disorders
Screening of newborns or individuals with a family history of hemoglobinopathies