HBAC

HbAC, or hemoglobin A/C, refers to the genetic state in which a person carries one normal adult hemoglobin allele (HbA) and one sickle-related/variant allele HbC. The HbC mutation occurs in the beta-globin gene (HBB) and involves a substitution of lysine for glutamic acid at position 6 of the beta chain. HbC is inherited in an autosomal recessive pattern; individuals with HbA/HbC have one normal and one variant beta-globin gene.

In individuals with HbA/HbC, the clinical course is typically benign. Most people are asymptomatic and lead normal lifestyles. Mild, nonspecific signs such as slight anemia or mild splenomegaly may be present in some cases, but painful crises or significant hemolysis are uncommon as seen in some other beta-globin disorders. The presence of HbC alters red blood cell morphology, and target cells may be observed on blood smear, but polymerization and sickling are not a prominent feature of HbAC.

Diagnosis is usually established by hemoglobin analysis, such as electrophoresis or high-performance liquid chromatography (HPLC), which shows both HbA and HbC as the predominant hemoglobins. HbA is typically around 60% and HbC around 40% in HbA/HbC individuals. Genetic testing of the HBB gene can confirm the diagnosis and distinguish HbC from other beta-globin variants.

Management is generally not required beyond routine health care. Genetic counseling is advised for affected individuals and their families, particularly for family planning. HbAC is most prevalent in populations from regions where the HbC allele is common, such as parts of West Africa.