Lagerström-Fermér M, Pettersson U, Landegren U
Department of Medical Genetics, University of Uppsala, Sweden.
Genomics. 1993 Jul;17(1):89-92. doi: 10.1006/geno.1993.1287.
A mutation that disrupts the gene for one of the major proteins in tooth enamel has been investigated. The mutation is located in the amelogenin gene and causes X-linked amelogenesis imperfecta, characterized by defective mineralization of tooth enamel. We have isolated the breakpoints of a 5-kb deletion in the amelogenin gene on the basis of nucleotide sequence information located upstream of the lesion, using a technique termed capture PCR. The deletion removes five of the seven exons, spanning from the second intron to the last exon. Only the first two codons for the mature protein remain, consistent with the relatively severe phenotype of affected individuals in the present family. The mutation appears to have arisen as an illegitimate recombination event since of 11 nucleotide positions immediately surrounding the two breakpoints, 9 are identical.
人们对一种破坏牙釉质中一种主要蛋白质基因的突变进行了研究。该突变位于釉原蛋白基因中，会导致X连锁型牙釉质发育不全，其特征是牙釉质矿化缺陷。我们利用一种称为捕获PCR的技术，根据位于病变上游的核苷酸序列信息，分离出了釉原蛋白基因中一个5kb缺失的断点。该缺失去除了七个外显子中的五个，范围从第二个内含子到最后一个外显子。成熟蛋白仅保留了前两个密码子，这与本家族中受影响个体相对严重的表型一致。由于紧邻两个断点的11个核苷酸位置中有9个相同，该突变似乎是作为一次异常重组事件出现的。
