Yuan C F, Lin C Y, Chen T W, Yang M L, Ng H T
Department of Obstetrics and Gynecology, Veterans General Hospital-Taipei, Taiwan, R.O.C.
Zhonghua Yi Xue Za Zhi (Taipei). 1997 Sep;60(3):125-9.
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic diseases of human. Traditionally, ADPKD is diagnosed by ultrasonography, computed tomography (CT) or magnetic resonance imaging (MRI) of kidneys for the presence of renal cysts. Individuals who carry the defective gene but have not yet developed cysts in kidney may not be diagnosed. Genetic analysis reveals it to be caused mostly by a single-gene disorder of a genetic locus, designated PKD1. Recently, the genetic locus involving PKD1 has been identified on chromosome 16p13.3, and has been cloned and completely sequenced.
A pair of primers, KG8-CA, located between D16S84 and D16S125, was selected and synthesized for the polymerase chain reaction (PCR) to identify individuals who may carry the defective locus. The sequence of KG8-CA primers, was 5'-CTCCCAGGGTGGAGGAAGGTG-3' and 5'-GCAGGCACAGCCAGCTCCGAG-3'. PCR products were analyzed in denaturing condition, using gel containing 8% acrylamide and 7M urea. Autoradiography was carried out to interpret the results.
Four Chinese families with history of ADPKD showed different DNA patterns in individuals with ADPKD and in normal individuals. Among the members in four families with history of ADPKD, every individual shared a common DNA band, suggesting that this band was derived from normal PKD1 allele. On the other hand, individuals diagnosed to have ADPKD showed one or two additional DNA bands which migrated differently from the common DNA band and should therefore be derived from defective ADPKD allele. Previous studies have shown that the ADPKD allele is highly polymorphic, as was evident in these family studies.
Among the members from these four families, some were clinically normal and had DNA pattern that was typical to patients with ADPKD. These individuals might carry the defective PKD1 allele but have not yet developed the ADPKD symptoms. Therefore, the method described in this study has diagnostic values for pre-symptomatic individuals as well as for patients already diagnosed with ADPKD.
常染色体显性多囊肾病（ADPKD）是人类最常见的遗传性疾病之一。传统上，ADPKD通过肾脏超声、计算机断层扫描（CT）或磁共振成像（MRI）检查肾脏中是否存在肾囊肿来诊断。携带缺陷基因但尚未在肾脏中形成囊肿的个体可能无法被诊断出来。基因分析显示，它主要由一个名为PKD1的基因座的单基因疾病引起。最近，涉及PKD1的基因座已在染色体16p13.3上被鉴定出来，并已被克隆和完全测序。
选择并合成一对位于D16S84和D16S125之间的引物KG8-CA，用于聚合酶链反应（PCR），以鉴定可能携带缺陷基因座的个体。KG8-CA引物的序列为5'-CTCCCAGGGTGGAGGAAGGTG-3'和5'-GCAGGCACAGCCAGCTCCGAG-3'。PCR产物在变性条件下，使用含有8%丙烯酰胺和7M尿素的凝胶进行分析。通过放射自显影来解释结果。
四个有ADPKD病史的中国家庭在ADPKD患者和正常个体中显示出不同的DNA模式。在四个有ADPKD病史的家庭成员中，每个个体都有一条共同的DNA带，表明这条带来自正常的PKD1等位基因。另一方面，被诊断患有ADPKD的个体显示出一条或两条额外的DNA带，其迁移方式与共同的DNA带不同，因此应该来自缺陷的ADPKD等位基因。先前的研究表明，ADPKD等位基因具有高度多态性，在这些家庭研究中很明显。
在这四个家庭的成员中，一些人临床正常，但具有ADPKD患者典型的DNA模式。这些个体可能携带缺陷的PKD1等位基因，但尚未出现ADPKD症状。因此，本研究中描述的方法对症状前个体以及已被诊断患有ADPKD的患者具有诊断价值。
