Universiti Sains Malaysia, School of Dental Sciences, Department of Medical Microbiology and Parasitology, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.
Hospital Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
Malays J Pathol. 2024 Aug;46(2):321-324.
Haemoglobin (Hb) Quong Sze is a non-deletional α-thalassaemia subtype that occurs due to missense mutation at codon 125 of the HBA2 gene. Interaction between Hb QS with Southeast Asian double α-globin gene deletion results in non-deletional HbH disease, which is more severe than deletional HbH.
A 3-month-old baby boy was presented with neonatal anaemia and mild hepatomegaly. Full blood count revealed severe hypochromic microcytic anaemia. There was an abundance of HbH inclusion bodies in his red blood cells. High-performance liquid chromatography showed a reduced HbA2 level with the presence of pre-run peak. Capillary electrophoresis showed the presence of HbH and Hb Barts. Molecular analysis found a common α-thalassaemia (--) in one allele and mutation in codon 125 in the other allele.
Non-deletional HbH disease due to a combination of deletional and non-deletional mutations may present with severe clinical manifestations than those with deletion mutations, which warrants accurate diagnosis using molecular techniques.
血红蛋白 Quong Sze（HbQS）是一种非缺失型α-地中海贫血亚型，是由于 HBA2 基因密码子 125 的错义突变引起的。HbQS 与东南亚双重α-珠蛋白基因缺失相互作用导致非缺失型 HbH 病，其严重程度甚于缺失型 HbH 病。
一名 3 个月大的男婴因新生儿贫血和轻度肝肿大就诊。全血细胞计数显示严重低色素性小细胞性贫血。其红细胞中存在大量 HbH 包涵体。高效液相色谱显示 HbA2 水平降低，且存在预运行峰。毛细管电泳显示存在 HbH 和 Hb Barts。分子分析发现一条等位基因存在常见的α-地中海贫血（--），另一条等位基因存在密码子 125 的突变。
由于缺失和非缺失突变的组合导致的非缺失型 HbH 病可能比缺失突变的临床表现更严重，因此需要使用分子技术进行准确诊断。
