Schneppenheim R, Thomas K B, Krey S, Budde U, Jessat U, Sutor A H, Zieger B
Universitäts-Kinderklinik Kiel, Germany.
Hum Genet. 1995 Jun;95(6):681-6. doi: 10.1007/BF00209487.
A screening project to identify candidate molecular defects causing von Willebrand disease type IIC (VWD IIC) in a German family was carried out using polymerase chain reaction (PCR) amplification of all 52 exons of the von Willebrand factor (VWF) gene, subsequent electrophoresis of single and double stranded DNA and direct sequencing of PCR products with aberrant electrophoretic patterns. Only one candidate mutation, G550R, caused by a G-->A transition, was detected in exon 14 of the pro-VWF gene sequence. This mutation was not found on 200 chromosomes of normal individuals. The propositus was homozygous for the mutation and for an extended intragenic haplotype, composed of eight polymorphic markers. Further family members were heterozygous for the mutation and were phenotypically normal or only mildly affected, in accordance with the recessive pattern of inheritance for VWD type IIC. The mutation could influence one of the presumed active centers for the suspected multimerizing enzymatic activity of pro-VWF localized in the D1 and D2 domain, which corresponds to exon 5 and exon 14 of the VWF gene.
开展了一项筛查项目，以确定德国家庭中导致IIC型血管性血友病（VWD IIC）的候选分子缺陷。该项目采用聚合酶链反应（PCR）扩增血管性血友病因子（VWF）基因的所有52个外显子，随后对单链和双链DNA进行电泳，并对具有异常电泳图谱的PCR产物进行直接测序。在前体VWF基因序列的第14外显子中，仅检测到一个由G→A转换引起的候选突变G550R。在200条正常个体的染色体上未发现该突变。先证者对于该突变以及由八个多态性标记组成的扩展基因内单倍型是纯合的。根据IIC型VWD的隐性遗传模式，其他家庭成员对于该突变是杂合的，并且表型正常或仅受到轻微影响。该突变可能影响位于D1和D2结构域（对应于VWF基因的第5外显子和第14外显子）中的前体VWF推测的多聚化酶活性的假定活性中心之一。
