Evaluation of a Patient with Hemoglobin S and Elevated Hemoglobin F

 

Syndromes associated with hemoglobin S and elevated hemoglobin F:

(1) homozygous hemoglobin S (sickle cell disease)

(2) hemoglobin S and beta0-thalassemia

(3) heterozygous hemoglobin S (sickle cell trait) and hereditary persistence of hemoglobin F (HPHF)

 

In Blacks the most common form of hereditary persistence of hemoglobin F encountered is the heterozygous deletional trait, which is associated with pancellular (homocellular) distribution of the hemoglobin F.

 

Findings	Sickle Cell Disease or Sickle-Thalassemia	Sickle Cell Trait and Heterozygous HPHF
clinical	symptomatic, often from a young age	benign
percent hemoglobin F	5 to 30%	20 to 40%
distribution of hemoglobin F in RBCs	heterocellular	homocellular

 

The presence of sickle cell trait and the nondeletional form of hemoglobin F would give a hemoglobin F level comparable to sickle cell disease or sickle-thalassemia. It could also show a heterocellular distribution of hemoglobin F. However, it would have a relatively benign course.