目的 通过研究正常人群中运动神经元存活蛋白1(survival of motor neuron 1，SMN1)和运动神经元存活蛋白2(survival of motor neuron 2，SMN2)基因拷贝数的分布来探讨SMN基因与脊髓性肌萎缩症(spinal muscular at-rophy，SM A)的相关性。方法 应用荧光PCR-毛细管电泳法对1 056名河南汉族健康育龄个体(女性811人、男性245人)进行SMN1和SMN2基因7号外显子(SMN1-E7;SMN2-E7)的拷贝数检测，并对拷贝数组合基因型进行分析。结果 女性携带率为0。023、男性携带率为0。024、总人群携带率为0。024，携带者的分布不存在性别差异(P＞0。05)。共检测到14种SMN1-E7，SMN2-E7拷贝数的基因型组合，分别是1∶1到1∶3三种、2∶0到2∶4五种、3∶0到3∶3四种、4∶0和4∶1两种。SMN1-E7的拷贝数分布从1到4，而SMN2-E7的拷贝数分布从0到4，且SMN2-E7为0拷贝的分布频率为0。038。SMN1和SMN2基因7号外显子的拷贝数之和最多为6。结论 SMA携带者分布无性别差异，SMN2基因的纯合缺失不会导致SMA疾病的发生。
Study on copy number variations of SMN1 and SMN2 genes in normal individuals
Objective To investigate the correlation between spinal muscular atrophy(SMA)genes and survival of mo-tor neuron(SMN)by studying the distribution of survival motor neuron 1(SMN1)and survival motor neuron 2(SMN2)gene copy numbers in the normal population.Methods Fluorescence PCR capillary electrophoresis was used to detect the copy number of exon 7 of SMN1 and SMN2 genes in 811 healthy women and 245 healthy men of Henan Han ethnici-ty,the genotypes of different copy number combinations were analyzed.Results In this study:The carrier frequency was 0.023 for females,0.024 for males,and 0.024 for the total population.There was no gender difference in the dis-tribution of carriers(P＞0.05).Fourteen combination genotypes of SMN1-E7,SMN2-E7 copy numbers were detected in this study,including three types from 1∶1 to 1∶3,five types from 2∶0 to 2∶4,four types from 3∶0 to 3∶3,and two types from 4∶0 to 4∶1.The copy number distribution of SMN1-E7 ranged from 1 to 4,while the copy number distribution of SMN2-E7 ranged from 0 to 4,and the distribution frequency of SMN2-E7 with 0 copies was 0.038.The maximum sum of copy numbers for exon 7 of SMN1 and SMN2 genes was 6.Conclusion There is no gender difference in the dis-tribution of SMA carriers,and homozygous deletion of the SMN2 gene can not lead to the occurrence of SMA disease.
Spinal muscular atrophySurvival of motor neuronSurvival motor neuron 1Survival motor neuron 2
NETL
NSTL
万方数据
