Hb H Hydrops Fetalis Syndrome Caused by Association of the − −^SEA Deletion and Hb Constant Spring (HBA2: c.427T > C) Mutation in a Chinese Family

Abstract

Hb Constant Spring (Hb CS; HBA2: c.427T > C) is an unstable hemoglobin (Hb) variant that results from a nucleotide substitution at the termination codon of the α2-globin gene. Compound heterozygosity for α⁰-thalassemia (α⁰-thal) and Hb CS (− −^SEA/α^CSα) results in Hb H/Hb CS disease, which is generally characterized with mild hemolytic anemia, jaundice, and splenomegaly. Here, we describe one case with Hb H/Hb CS disease that presented with fetal anemia and fetal hydrops, known as Hb H (β4) hydrops fetalis. This is the first report of fetal hydrops caused by association of the − −^SEA deletion and the α^CSα mutation. Our study highlights the significance of watchful observation using a serial ultrasound method and care of pregnant women who have fetuses found to carry Hb H/Hb CS disease during pregnancy, to guard against the occurrence of fetal hydrops.

• α-Globin gene
• α-thalassemia (α-thal)
• Hb H hydrops fetalis
• Hb H/Hb CS disease

Acknowledgements

We are grateful to our current laboratory members for their helpful comments on the manuscript.

Declaration of interest

The study was supported by grants from the Health Department of Guangxi Province (Zhong 2012020), Guangxi Science and Technology Department (Gui 14124004-1-5) and the National Science Foundation of China (81260093). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.