RESUMO
Hemoglobin E (HbE), alpha-thalassemia, and beta-thalassemia are common among Southeast Asians and often occur in compound heterozygous states that complicate neonatal screening. We describe a kindred with alpha-thalassemia-1, HbE, and beta zero-thalassemia. The proband had HbE/beta zero-thalassemia, with severe anemia and failure to thrive. His father also had HbE/beta zero-thalassemia but had coinherited alpha-thalassemia-1 and was free of symptoms.
Assuntos
Hemoglobina E/genética , Talassemia alfa/genética , Talassemia beta/genética , Adulto , Sudeste Asiático/etnologia , Pré-Escolar , Feminino , Aconselhamento Genético , Genótipo , Heterozigoto , Humanos , Recém-Nascido , Masculino , Triagem Neonatal , Talassemia alfa/complicações , Talassemia alfa/etnologia , Talassemia beta/complicações , Talassemia beta/etnologiaRESUMO
We describe a Canadian infant of Jamaican descent who presented with mild anemia. Hb electrophoresis revealed Hb S and an unknown Hb variant that migrated slightly faster than Hb S on cellulose acetate. Molecular studies of the family indicated that the proband is a compound heterozygote for Hb S and Hb Caribbean. Hb Caribbean has previously been characterized as a mildly unstable hemoglobin with low oxygen affinity, due to a Leu-->Arg substitution at amino acid residue 91. The present study establishes the molecular basis for Hb Caribbean (beta 91, CTG-->CGG) and confirms that Hb S/Hb Caribbean syndrome is not associated with serious clinical manifestations.