Point mutations which should not be overlooked in Hb H disease.

BACKGROUND: Hb H disease is an alpha-thalassemia (α-thal) syndrome characterized by chronic hemolytic anemia that occurs when three of total four α-globin genes lost their function due to completely deletions or different kind of mutations.

OBJECTIVE: We here described 66 patients who have been diagnosed for Hb H disease during the last five years in our center. The genotypes involving point mutations present more severe phenotype than deletional forms that make them of primary important to health management.

STUDY DESIGN: Hb H subjects carry different α-globin genotypes including deletional and non-deletional mutations showing heterogenous clinical manifestations.

RESULTS: The Hb H patients presenting a wide range of phenotype carried different deletional, non-deletional mutations or compound heterozygosity of them.

CONCLUSION: We emphasize the importance of some point mutations responsible for more severe form of Hb H disease in Iranian population and the necessity for consideration of prenatal diagnosis (PND) in high-risk couples.