First Case of a Compound Heterozygosity for Two Nondeletional α-Thalassemia mutations, Hb Constant Spring and Hb Quong Sze

• Published in: Hemoglobin Vol. 40; no. 3; pp. 210 - 212
• Main Authors: Zhou, Jian-Ying, Yan, Jin-Mei, Li, Jian, Li, Dong-Zhi
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 03.05.2016
• Subjects: Adult; alpha-Thalassemia - genetics; Anemia - genetics; compound heterotozygosity; Hb Constant Spring (Hb CS); Hb Quong Sze (Hb QS); Hemoglobins, Abnormal - genetics; Homozygote; Humans; Mutation - genetics; nondeletional; Phenotype; α-Thalassemia (α-thal); Hb Quong Sze (Hb QS); compound heterotozygosity; Hb Constant Spring (Hb CS); α-Thalassemia (α-thal); nondeletional
• ISSN: 0363-0269; 1532-432X
• DOI: 10.3109/03630269.2016.1148614

Nondeletional α-thalassemia (α-thal) is the result of point mutations in critical regions of the α-globin genes, affecting mRNA processing, mRNA translation, or α-globin stability. Hb Constant Spring (Hb CS, HBA2: c.427T > C) is the most common nondeletional α-thal that results from a nucleotide substitution at the termination codon of the α2-globin gene. Hb Quong Sze (Hb QS, HBA2: c.377T > C) is another nondeletional α-thal in South China with the missense mutation at codon 125 of the α2-globin gene making this hemoglobin (Hb) variant highly unstable. Although homozygosity for Hb CS (α CS α/α CS α) or Hb QS (α QS α/α QS α) has been reported, clinical pictures vary from severe hemolysis that developed early in life to only mild anemia, no clinical phenotypic data of compound heterozygosity for Hb CS/Hb QS (α CS α/α QS α) has been described. In this report we describe an adult case with such a compound heterozygosity who presented with a mild α-thal.