β-地中海贫血基因分析与临床

The genotype and clinical features of β-thalassemia

目的：探讨β-地中海贫血的基因型与临床表现之间的关系。方法：小细胞低色素贫血患儿外周血用血红蛋白电泳法作临床诊断。以8种中国人最常见的β地中海贫血寡核苷酸探针阵列用荧光斑点杂交法对患儿及其父母进行基因突变分析。结果：24例患儿中重型地中海贫血14例，βE3例，轻型7例，发现10种基因突变类型。轻型者其基因型全部为杂合子，重型1例是纯合子（17/17），13例是双重杂合子。他们的临床表现为起病早，贫血程度重，HbF显著增高，需要长期输血才能维持其生命和生长发育。βE中1例为重型，2例为中间型。结论：β-地中海贫血的临床表现和其基因型密切相关，本地区重型β-地中海贫血以双重杂合子多见，患儿双亲均为携带者。本组病例中以CD17，IVS-Ⅱ-654，CD71-72基因突变发生率较高。βE的患儿临床表现差异较大。

Objective: To study the genotype of β-thalassemia in Chongqing area. Methods: 24 patients with β-thalassemia were diagnosed by hemoglobin electrophoresis from patients with hypochromic microcytic anemia . Fluorescence dot blot hybridization was performed in all patients and their parents by 8 most commonly used oligonucleotide probes in China. Results: 14 patients withβ-thalassemia major, 7 patients withβ-thalassemia minor and 3 patients withβ-thalassemia combined with HbE were diagnosed . 10 kinds of gene mutations were identified among these patients. The genotypes inβ-thalassemia minor are all heterozygotes. One homozygote and 13 double heterozygotes were found with patients inβ-thalassemia major. Clinical features of β-thalassemia major include early episode, severe anemia and increased HbF level. Long-term transfusion was all required for these patients to maintain the life and growth. Among 3 patients withβ-thalassemia combined with HbE, one is with thalassemia major and the rest are with thalassemia intermedia. Conclusion: The clinical features of β-thalassemia is closely related to the genotype. Double heterozygote is the most common genotype in Chongqing area and the parents of the patients are all carrier. The mutation of CD17, IVS-Ⅱ-654 and CD71-72 are the most common genotypes in this study. The clinical features in the patients withβ-thalassemia combined with HbE varied greatly.