广东省东莞地区地中海贫血产前筛查及产前诊断体系的建立

Establishment of the system of prenatal screening and prenatal diagnosis of thalassemia in Dongguan city

目的减少东莞地区中重症α和β地中海贫血儿的出生率，提高出生人口素质。方法采用红细胞平均体积测定对2218例育龄夫妇进行地中海贫血的筛查，并用跨越断裂点聚合酶链反应（Gap—PCR）技术及随机双盲试验（RDB）法分别对α及β地中海贫血进行基因诊断。结果检出地中海贫血277例，发生率12．49％。α地中海贫血220例，基因携带率为9．92％；其中：^--SEA／αα198例，-α^3.7／αα11例，-α^4.2／αα7例。检出B地中海贫血57例，基因携带率为2．57％。检出β基因突变类型依次为CD41／42（-TrCT）27例，IVS2nt-654（C→T）14例，CD17（A→T）10例，-28（A→G）4例，TATAbox29（A→G）1例，CD71／72（＋A）1例。对42对夫妇均为地中海贫血携带者的胎儿进行产前诊断，3例为Bart水肿胎终止妊娠，7例为13地中海贫血纯合子而终止妊娠。结论通过产前筛查地中海贫血及基因诊断，可确诊重症患儿并及时终止妊娠。建立切实可行的人群筛查．高风险夫妇产前诊断一选择性流产体系，可有效避免重症患儿的出生，对提高人口素质具有重要意义。

Objective To reduce birthrate of severe thalassemia children of this area and improve population diathesis. Methods The red blood cell indices analysis was carried out on all of the samples of 2 218 couples. Gap- PCR and RDB method were used for ct-thalassemia genotyping and β-thalassemia genotyping. Results 277 cases of thalassemia（ 12.49% ） were identified among the total eases. 220 cases were with ct-thalassemia（9.92% ） ,which in- cluding 198 cases of--SEA/act, 11 cases of-α3.7/,7 cases of-α42/αα,57 cases were with β-thalassemia（2.57% ） ,the types of mutation were CIM1/42（-TFCT） ,IVS2nt-654（ C→T）, CD17 （ A→T）,-28 （ A→G）, TATAbox29 （ A→G）, CD71/72（ ＋ A）. 42 carrier couples were detected for thalassemia and the fetuses were subjected prenatal diagnosis ：3 cases of Bart＇s edema, 7 cases of β-thalassemia homozygote. Conclusions Neonates with major thalassemia can be clarified and even avoided by screening the incidence and types of genicmutations. Thus setting up the system of pre- natal screening-prenatal diagnosis-selective abortion is effective to avoid the birth of neonates. And it is vital to im- prove the quality of human being.