Hereditary Persistence of Hemoglobin F (HPHF) involves the presence of hemoglobin F beyond early infancy and into adulthood.


Clinical features of HPHF:

(1) usually asymptomatic

(2) normal RBC count

(3) normal hemoglobin concentration

(4) normal MCV


Many affected patients are African or are of African descent.


Types of HPHF:

(1) deletional: deletion involving the delta and beta globin genes in chromosome 11, making it a form of thalassemia

(2) nondeletional: variable, including a single nucleotide substitution in the promoter region of a gamma globin gene

Form of HPHF

Percent Hemoglobin F

heterozygous deletional


homozygous deletional


heterozygous nondeletional

3 to 30%


The distribution of increased hemoglobin F in red cells of a patient with heterozygous deletional HPHF is pancellular (homocellular, affects all cells). The nondeletional form may show a variable distribution (heterocellular) or a homocellular distribution.


Problems for a patient with HPHF

(1) Iron deficiency can result in findings that overlap with with delta/beta thalassemia.

(2) Detection of fetal red blood cells in an affected woman following delivery is difficult.


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