Hb Savaria [α49(CE7)Ser→Arg;HBA2: c.150C > A]: A New Case and Complete Description

Abstract

Hb Savaria [α49(CE7)Ser→Arg; HBA2: c.150C > A] is a rare hemoglobin (Hb) variant, initially described in Eastern Europe but present worldwide. It belongs to that class of variants which can be confused with Hb S [β6(A3)Glu→Val; HBB: c.20A > T] by automated protein analysis and thus needs special tests for proper identification. Because it could arise from different nucleotide substitutions and according to the rules of the Human Genome Variation Society (HGVS) nomenclature, three 'Hb Savaria' variants are possible. In the case reported here it resulted from the HBA2: c.148A > C change.

Next‐generation sequencing improves molecular epidemiological characterization of thalassemia in Chenzhou Region, P.R. China

“…Three rare abnormal hemoglobin variants, Hb Zurich‐Langstrasse, Hb Yusa, and Hb Genova, were reported for the first time in China. Moreover, we found a new case of Hb Savaria with a novel mutation HBA2:c.150C>G, which was predicted as one of the three mutated forms of Hb Savaria before …”

“…Theoretically, Hb Savaria has three different variants, including HBA2:c.150C‐>A, HBA2:c.148A‐>C, and HBA2:c.150C‐>G. HBA2:c.150C‐>A, which is present in HbVar, was firstly reported in a female from Kenya . Another variant HBA2:c.148A‐>C was recently reported in France . The last form of mutation HBA2:c.150C‐>G was firstly found in a woman with normal hematological parameters in our study.…”

Evidence for a gene conversion in a Hb Arya Carrier [α codon 47 Asp>Asn, Hb A1(or Hb A2):c.142 G>A]

“…Because of the number of patients to screen for Hb disease, protein analysis remains the cheapest method. However, safe differential diagnosis requires more than CE-HPLC and CE to differentiate the numerous variants or variant association that are known to mimic pathogenic ones [2,3].…”

“…However, in many cases, it is not possible to correctly identify a variant just by using the data obtained from CE-HPLC and CE. This fact is of importance when pathologic variants are involved and particularly Hb S (b6 Glu>Val HBB:c.20A>T) because variants which mimic Hb S are regularly reported [2,3].…”