Hb Florida: A novel elongated C‐terminal β‐globin variant causing dominant β‐thalassemia phenotype

• Published in: American journal of hematology 2006-05, Vol.81 (5), p.358-360
• Main Authors: Weinstein, B.I., Erramouspe, B., Albuquerque, D.M., Oliveira, D.M., Kimura, E.M., Costa, F.F., Sonati, M.F.
• Format: Article
• Language: English
• Subjects: Anemias. Hemoglobinopathies; Base Sequence; beta-Thalassemia - blood; beta-Thalassemia - genetics; Biological and medical sciences; Child; Diseases of red blood cells; dominantly inherited β‐thalassemia; elongated β‐globin variant; Female; Frameshift Mutation; Globins - genetics; Hb Florida; Hematologic and hematopoietic diseases; Hemoglobins, Abnormal - genetics; Humans; Medical sciences; Sequence Deletion
• ISSN: 0361-8609; 1096-8652
• DOI: 10.1002/ajh.20561

We report here a new frameshift mutation in exon 3 of the β‐globin gene, a single nucleotide deletion (‐C) in between codons 140/141 (GCC/CTG→GCC/TG), found in an 8‐year‐old Argentinean girl with clinical picture of thalassemia intermedia. It leads to a β‐chain that is elongated to 156 amino acids [(141)Trp‐Pro‐Thr‐Ser‐Ile‐Thr‐Lys‐Leu‐Ala‐Phe‐Leu‐Leu‐Ser‐Asn‐Phe‐(156)Tyr‐COOH]. The resulting hemoglobin, which we named Hb Florida, was not detected in peripheral blood; however, erythroid hyperplasia and dyserythropoiesis with large inclusion bodies on methyl violet staining were observed in bone marrow, suggesting that this is a hyperunstable variant producing a dominant β‐thalassemia phenotype, since the other β‐allele was completely normal. Am. J. Hematol. 81:358–360, 2006. © 2006 Wiley‐Liss, Inc.