遗传性痉挛性截瘫2型一家系PLP1基因突变分析

Analysis of PLP1 gene mutation in a Chinese family with spastic paraplegia 2

目的分析并确定一个遗传性痉挛性截瘫2型(spastic paraplegia 2,SPG2)家系蛋白脂蛋白1(proteolipid protein 1,PLP1)基因突变与遗传学特征。方法收集先证者及其家系成员临床资料,采用聚合酶链反应和DNA直接测序方法进行PLP1基因突变检测,确定基因突变位点,分析基因型与表型的关系。结果本家系先证者临床符合SPG2诊断。测序结果显示先证者PLP1基因第3外显子c.388C>T(p.His130Tyr)半合子改变,先证者之母为本位点的杂合改变。结论本家系SPG2先证者为PLP1基因半合子突变致病,遗传自表型正常携带者的母亲。本研究明确了本家系PLP1基因突变与遗传特征,为准确的遗传咨询和进一步的产前诊断打下了基础。

Objective To explore proteolipid protein 1（PLP1）gene mutation and genetic characteristics in a Chinese family with spastic paraplegia 2（SPG2）. Methods Clinical data of the proband and other family members as well as genomic DNA samples were collected. The PLP1 gene mutation was detected by polymerase chain reaction（PCR） and direct DNA sequencing,and the genotype-phenotype correlation was analyzed. Results The clinical data of proband met the criteria of SPG2. The c. 388C T（p. His130Tyr）hemizygote mutation was identified in exon 3 of PLP1 from the proband. The c. 388C T（p. His130Tyr）heterozygous change was found in proband＇s mother. Conclusion This study has proved the c. 388C 〉 T（ p. His130Tyr） hemizygous mutation of PLP1 from proband which is inherited from his mother. The results might provide the exact genetic counseling and the prenatal diagnosis for this SPG2 pedigree.