来宾市3个罕见地中海贫血家系的产前诊断

Prenatal diagnosis of three rare thalassemia families in Laibin city

目的对来宾市3对一方携带罕见地中海贫血(以下简称地贫)基因突变类型、另一方携带常见地贫基因突变类型的同型地贫夫妇进行产前诊断。方法抽取家系成员的外周血2 mL进行血红蛋白(hemoglobin, Hb)组分分析与血常规检测;采用多重裂口聚合酶链反应(gap-polymerase chain reaction,Gap-PCR)和PCR结合反向斑点杂交法(polymerase chain reaction and reverse dot blot, PCR-RDB)对外周血和羊水所提取的DNA进行常见地贫基因突变类型检测;以DNA测序方法进行罕见地贫基因突变类型鉴定。结果 3个家系检测到3种罕见地贫基因突变类型为:(1)α2基因编码区起始密码子突变(ATG>GTG),(2)β珠蛋白IVS-II-5(G>C),(3)β珠蛋白IVS-I(-2)orCD30(A>G);产前诊断3个胎儿均为罕见地贫基因合并常见地贫基因患者。结论罕见地贫基因合并常见地贫基因引起的贫血必须引起优生遗传咨询医生的注意,遗传咨询和产前诊断是防止严重地贫患儿分娩最有效的途径。

Objective To investigate the prenatal diagnosis of three homotypic thalassemia couples with rare thalassemia gene mutation type and common thalassemia gene mutation type. Methods 2 mL peripheral blood of family members were collected for Hb component analysis and routine blood test. Multiple slit polymerase chain reaction(Gap-PCR) and PCR combined with reverse dot blot(PCR-RDB) were used to detect common thalassemia gene mutations in DNA extracted from peripheral blood and amniotic fluid. DNA sequencing was used to identify the type of rare thalassemia gene mutation. Results Three rare poverty gene mutations were detected in three families:(1)α 2 gene initiation codon mutation(ATG>GTG),(2)β globin IVS-II-5(G>C),(3)β globin IVS-I(-2) or CD30(A>G);antenatal diagnosis the three fetuses were all patients with rare thalassemia gene combined with common thalassemia gene. Conclusion The anemia caused by rare and common thalassemia genes must be paid attention to by the genetic counseling doctors of eugenics. Genetic counseling and prenatal diagnosis are the most effective ways to prevent severe thalassemia children from delivery.