A rare case of Hb H disease caused by compound heterozygous for α thalasemia and Hb Quong Sze in Chinese Indonesian proband: a case report

• DOI: 10.15562/bmj.v8i2.1411
• Publication Date: 2020-04-22T05:04:41Z
• Authors: Nyoman Suci Widya...; Ita Margaretha Na...; Edward L Kurnia; Dwi Retnoningrum; Imam Budiwiyono
• Keywords: Mean corpuscular hemoglobin; Compound heterozygosity; Alpha-thalassemia; Proband

Background: Hemoglobin H (HbH) disease is alpha thalassemia characterized by inactivation of three four α-globin genes due to deletions with or without non-deletional α-thalassemia. Hb Quong Sze (Hb QS) a very rare α-thalassemia in Indonesia caused CTGLeu>CCGPronucleotide substitution at codon 125 α2 globin gene generating highly unstable hemoglobin. Compound heterozygosity for QS and Southeast Asian double deletion (--SEA) result accumulation b-globin tetramers, causing hemolytic anemia.Case Report: A 49 years old Chinese Indonesian female was assessed screening. The phenotype the proband normal only mild anemia noticeable. She experienced blood transfusion five ago sudden fall hemoglobin level after malarial infection. Complete count found 8.3 g/dL, Mean Corpuscular Volume (MCV) 65.7 fl (MCH) 17.1 pg. HbH suggested abundant inclusion bodies red cells. Microcapillary electrophoresis showed 31.8 %, Bart 0.4%, HbA 67.3% HbA2 0.5%. Molecular studies were carried out using multiplex polymerase chain reaction (PCR) method, common a0-thalassemia(--SEA) detected one allele. Direct sequencing analysis α1 revealed other allele.Conclusion: Non-deletional compound heterozygous of has low incidence Indonesia. An advanced molecular should be performed determine this mutation.