Lemmink H H, Schröder C H, Brunner H G, Nelen M R, Zhou J, Tryggvason K, Haagsma-Schouten W A, Roodvoets A P, Rascher W, van Oost B A
Department of Pediatrics, University of Hospital Nijmegen, The Netherlands.
Genomics. 1993 Aug;17(2):485-9. doi: 10.1006/geno.1993.1351.
The type IV collagen alpha 5 chain (COL4A5) genes of patients with Alport syndrome were tested for major gene rearrangements by Southern blot analysis, using COL4A5 cDNA clones as probes. In addition, individual exons were screened for small mutations by single-strand conformation polymorphism (SSCP) analysis. Four new COL4A5 mutations were detected. A duplication of the nine most 3' located nucleotides of exon 49 and the first nucleotide of intron 49 was identified in the COL4A5 gene of one patient. Two patients displayed single base substitutions leading to, respectively, a proline to threonine and an arginine to glutamine substitution in the C-terminal end. Both substitutions involve amino acids conserved through evolution. In COL4A5 intron 41 a mutation changing the splice acceptor site from AG to AA was identified. All mutations cosegregate with the clinical phenotype of Alport syndrome in affected family members. In a control population of 50 individuals tested by PCR-SSCP these mutations were never identified. Together with two mutations reported previously, a total of six mutations were found in 26 patients with Alport syndrome (23%) after systematic screening of about 30% of the COL4A5 coding region. The clinical features of these six patients are described in detail.
采用COL4A5 cDNA克隆作为探针，通过Southern印迹分析检测了Alport综合征患者的IV型胶原α5链（COL4A5）基因的主要基因重排。此外，通过单链构象多态性（SSCP）分析筛选各个外显子的小突变。检测到四个新的COL4A5突变。在一名患者的COL4A5基因中，发现外显子49最3'端的九个核苷酸和内含子49的第一个核苷酸发生了重复。两名患者出现单碱基取代，分别导致C末端的脯氨酸被苏氨酸取代和精氨酸被谷氨酰胺取代。这两种取代均涉及进化上保守的氨基酸。在COL4A5内含子41中，发现一个将剪接受体位点从AG变为AA的突变。所有突变均与患病家庭成员中Alport综合征的临床表型共分离。在通过PCR-SSCP检测的50名个体的对照人群中，未发现这些突变。在对约30%的COL4A5编码区进行系统筛选后，在26名Alport综合征患者（占比为23%）中总共发现了六个突变，其中包括先前报道的两个突变。详细描述了这六名患者的临床特征。
