A clinical update of compound heterozygosity for hemoglobin Hekinan II [a27(B8)Glu-Asp; HBA1: c.84G>T] variant in China

Lab Med. 2024 Sep 4;55(5):615-619. doi: 10.1093/labmed/lmae023.

Abstract

Background: Hemoglobin (Hb) Hekinan II (A27; Glu-Asp) is an α-chain variant, and its interaction with the common Southeast Asian (--SEA/) α-thalassemia (α-thal) deletion is rarely reported. This study provides a clinical update of Hb Hekinan II associated with (--SEA/) α-thal.

Methods: A total of 11 simple heterozygotes and 20 composite heterozygotes for Hb Hekinan II and (--SEA/) α-thal were included based on molecular diagnosis.

Results: Hb Hekinan II exhibited a significant increase in hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin content, but a decrease in red blood cell level compared with α+ thalassemia deletion. Compared with (--SEA/) α-thal, composite heterozygotes for Hb Hekinan II and (--SEA/) α-thal showed similar erythrocyte parameters. Both heterozygotes with and without (--SEA/) α-thal showed low Hb A2 level. Hb Hekinan II showed abnormal performance in high-performance liquid chromatography but not in capillary electrophoresis.

Conclusion: Hb Hekinan II is a benign Hb variant. The heterozygotes exhibit clinically asymptomatic coinheritance with (--SEA/) α-thal having comparable hematological phenotype to simple (--SEA/) α-thal. The combination of hematological and molecular analysis helped to improve the detection rate of this rare variant.

Keywords: Hb Hekinan II; compound heterozygosity; hemoglobin; α-thalassemia.

MeSH terms

  • Adult
  • China
  • Chromatography, High Pressure Liquid
  • Electrophoresis, Capillary
  • Erythrocyte Indices
  • Female
  • Hemoglobins, Abnormal* / genetics
  • Heterozygote*
  • Humans
  • Male
  • alpha-Thalassemia / blood
  • alpha-Thalassemia / diagnosis
  • alpha-Thalassemia / genetics

Substances

  • Hemoglobins, Abnormal