Objective A 47-year-old male proband suspected of β - thalassemia with symptoms such as anemia and splenomegaly was diagnosed by clinical examination in the Department of Hematology, Affiliated Haikou Hospital of Xiangya Medical College, and his family members were further studied and analyzed.
Methods The proband and 5 family members were detected by blood routine, spleen B-ultrasound, hemoglobin electrophoresis, Gap-PCR and high-throughput sequencing (NGS) to evaluate their anemia, splenomegaly and gene mutation. Sanger sequencing was used to verify the gene mutation detected by high-throughput sequencing. The genetic mode of the detected gene mutation was determined by pedigree linkage analysis.
Results The proband detected both HBB: c. 2T>G and HBB: c.- 113A>G mutations, in which HBB: c. 2T>G was a common β mutation, HBB: c.- 113A>G was a new mutation, HBB: c.- 113>G heterozygous mutation was detected in both his mother and son, and HBB: c. 2T>G heterozygous mutation was detected in his daughter. Except for the proband, other family members did not show obvious symptoms of thalassemia.
Conclusions HBB:c.2T>G heterozygous compound HBB:c.-113A> G heterozygous mutation can aggravate the clinical manifestations of β-thalassemia and then show splenomegaly. The discovery of this gene mutation enriches the database of thalassemia gene mutation. At the same time, more comprehensive detection techniques are of great significance for etiological diagnosis, treatment and genetic counseling of clinical patients after routine detection of thalassemia.
摘要： 目的 对海口市人民医院血液科一例 47 岁男性经临床检查存在贫血、脾大等症状的疑似 β 地中海贫血的先 证者进行病因确诊, 并对其家系成员进一步研究分析。 方法 采用血常规、脾脏 B 超、血红蛋白电泳、跨越断点 PCR (Gap-PCR) 和高通量测序 (next generation sequencing, NGS) 技术对先证者和 5 名家系成员进行检测, 评估他们贫血、脾 脏肿大和基因突变等方面的情况, 采用 Sanger 测序法对高通量测序所检测出的基因突变进行验证, 并通过家系连锁分 析确定所检测基因突变的遗传方式。 结果 先证者同时检测出 HBB:c.2T>G 和 HBB:c.-113A>G 两种突变, 其中 HBB: c.2T>G 为常见 β 突变, HBB:c.-113A>G 为新的突变, 其母亲及儿子均检出 HBB:c.-113A>G 杂合突变, 其女儿检出 HBB: c.2T>G 杂合突变, 除先证者外其他家系成员并未表现出明显的地贫症状。 结论 HBB:c.2T>G 杂合复合 HBB:c.-113A> G 杂合突变会加重 β 地贫的临床表现, 进而表现出脾大症状, 该基因突变的发现, 丰富了地贫基因突变数据库。全面的 检测技术应用于地贫常规检测对临床病人的病因确诊、治疗和遗传咨询都具有重要意义。