Misdiagnosis of Hb Constant Spring (α142, Term→Gln, TAA→CAA in α2) in a Hb H (β₄) Disease Child

Abstract

Hb Constant Spring (Hb CS; α142, Term→Gln, TAA→CAA in α2) is the most prevalent nondeletional α-thalassemia (thal) in Southeast Asian populations. It is difficult to detect on electrophoresis in its heterozygous state because of the low Hb CS levels. We found a case with Hb H (β₄) disease who, at birth, was initially assumed to have deletional α-thal mutations, but eventually proved to have a Hb CS defect.

Keywords:

• α-Thalassemia (thal)
• Nondeletional mutations
• Hb Constant Spring (Hb CS)