Wang Bing, Hu Dong-xu, Xia Jia-hui, Li Qi, Lu Guo-hua
Department of Surgery, the Second Affiliated Xiangya Hospital, Central South University, Changsha, Hunan, PR China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2003 Feb;20(1):1-4.
To analyze fibrillin-1 (FBN(1)) gene mutation in Chinese patients with Marfan syndrome(MFS) and to make a gene diagnosis by haplotype analysis for MFS.
Nine MFS families were analysed with single strand conformation polymorphism(SSCP) and DNA sequencing. With the use of four primers designed in the flanking sequences of each short-sequence tandem-repeat region in FBN(1) gene, the haplotype-segregation analysis for MFS(B) was performed.
In MFS(A)II(1), PCR-SSCP detected SSCP band alterations in exon 25 of FBN(1) gene; direct sequencing showed a small 13bp deletion, the deleted sequence being gcctctgcaccca at base 3243-3456 of cDNA. This mutation caused a frame-shift which was never seen in any unaffected members of the family, and it was a heterozygous mutation; neither of them was identified in 100 chromosomes from 50 normal control individuals. Haplotype-segregation analysis suggested that the disease was passed from Subject I(2) to Subject II(2), Subject II(3), Subject II(5) with the same allele in MFS B family, the proband's daughter also inherited the allele. These data indicated that MFS(B) family was linked to FBN(1) gene, the proband's daughter was an asymptomatic patient.
The combination of mutation analysis and haplotype analysis can provide more evidence for gene diagnosis.
分析中国马凡综合征（MFS）患者的原纤蛋白-1（FBN(1)）基因突变情况，并通过单倍型分析对MFS进行基因诊断。
采用单链构象多态性（SSCP）和DNA测序技术对9个MFS家系进行分析。利用在FBN(1)基因每个短串联重复序列区域侧翼序列设计的4条引物，对MFS（B）进行单倍型分离分析。
在MFS（A）II（1）中，PCR-SSCP检测到FBN(1)基因第25外显子的SSCP条带改变；直接测序显示有一个13bp的小缺失，缺失序列为cDNA第3243 - 3456位碱基处的gcctctgcaccca。该突变导致移码，在该家系所有未患病成员中均未发现，为杂合突变；在50名正常对照个体的100条染色体中均未检测到这两种突变。单倍型分离分析表明，在MFS B家系中，疾病从I（2）传递给II（2）、II（3）、II（5），携带相同等位基因，先证者的女儿也继承了该等位基因。这些数据表明MFS（B）家系与FBN(1)基因连锁，先证者的女儿为无症状患者。
突变分析与单倍型分析相结合可为基因诊断提供更多证据。
