Hb rio claro [β34(B16)Va1→Met]: A novel electrophoretically silent variant found in association with Hb hasharon [α47(CE5)Asp→His] and α-thalassemia-2 (-α^3.7)

Abstract

More than 700 hemoglobin (Hb) structural variants have been described. Most of those were originally detected by their abnormal electrophoretic pattern. They may or may not result in clinical manifestations. A significant proportion of these variants is caused by substitutions which do not change the electrical charge of the protein (1).The present work describes a new electrophoretically silent Hb variant detected by globin chain electrophoresis in a 4-year-old Caucasian Brazilian boy of Italian descent, and in his mother. This new variant has been identified as P34(B16)Val-+Met, and was found in association with Hb Hasharon [a47(CES)Asp+His] and a-thalassemia-2 (a-thal-2) (_a3 ', rightward deletion).

Investigating alpha-globin structural variants: a retrospective review of 135,000 Brazilian individuals

“…In one family, two individuals had both Hb Hasharon and Hb Rio Claro [HBA2:c.142G>C p.Asp47His; HBB:c.100G>A p.Val33Met], a beta-chain variant newly described in this laboratory. 16 Both individuals had microcytosis and hypochromia ( Table 2 ). In another family, Hb Hasharon was detected with one β + (IVS-I-110) and one β 0 (CD39) allele in the same individual, who presented with a typical clinical course of thalassemia intermedia ( Table 2 ).…”

Identificação e caracterização de variantes novas e raras da hemoglobina humana

“…A Hb Rio Claro, outra nova variante, foi encontrada em uma paciente também heterozigota da Hb Hasharon e, conseqüentemente, da talassemia α + . 21 As hemoglobinas D e J-Rovigo foram ainda detectadas em concomitância à talassemia β. 10 Esses resultados ilustram a expressiva variabilidade de hemoglobinas presente nas populações.…”