Hb Extremadura [β64(E8)Gly→Ser;β133(H11)Val→Leu]: A New Molecular Analysis

Abstract

Unstable hemoglobin (Hb) variants account for 9.5% of structural hemoglobinopathies. The majority of these unstable variants are the result of gene point mutations resulting in the substitution of a single amino acid by another. The presence of two mutations in the same allele is infrequent: of the 781 variants of the β-globin cluster described, only 32 are due to two point mutations (4.1%). Hb Extremadura is a structural variant that is included within the so-called unstable Hb anomalies. It was first described in 1989, employing the most up-to-date techniques available at that time, reversed phase high performance liquid chromatography (HPLC) to separate the abnormal chain (β^X) digesting it with trypsin and analysis of the fragments with an automatic analyzer.

• Unstable hemoglobin (Hb)
• Two mutations in the β chain globin
• Hemoglobinopathies