Hb H disease resulting from the association of an α-thalassemia allele [-(α)] with an unstable α-globin variant [Hb Icaria]: First report on the occurrence in Brazil.

Abstract

Hb H Disease is caused by the loss or inactivation of three of the four functional α-globin genes. Patients present chronic hemolytic anemia and splenomegaly. In some cases, occasional blood transfusions are required. Deletions are the main cause of this type of thalassemia ( α-thalassemia). We describe here an unusual case of Hb H disease caused by the combination of a common α(0) deletion [-( α) (20.5) ] with a rare point mutation (c.427T > A), thus resulting in an elongated and unstable α-globin variant, Hb Icaria, (X142K), with 31 additional amino-acid residues. Very high levels of Hb H and Hb Bart's were detected in the patient's red blood cells (14.7 and 19.0%, respectively). This is the first description of this infrequent association in the Brazilian population.

• Authors: Elza M Kimura, Denise M Oliveira, Kleber Fertrin, Valéria R Pinheiro, Susan E D C Jorge, Fernando F Costa, Maria de Fátima Sonati
• Journal: Genetics and molecular biology (Genet Mol Biol) Vol. 32 Issue 4 Pg. 712-5 (Oct 2009) ISSN: 1678-4685 [Electronic] Brazil
• PMID: 21637442 (Publication Type: Journal Article)