Kumatori A, Faizunnessa N N, Suzuki S, Moriuchi T, Kurozumi H, Nakamura M
Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan.
Genomics. 1998 Oct 15;53(2):123-8. doi: 10.1006/geno.1998.5510.
We cloned and characterized a genomic DNA fragment including the deletion junction of a chronic granulomatous disease patient with a 25-kb deletion extending to the 5' two-thirds of CYBB. The 3' breakpoint of the deletion exists in exon 7 of CYBB. A LINE-1 element lies at 5 kb upstream of CYBB in normal persons, and the 5' breakpoint of the deletion in the patient is in the LINE-1 element. There are no significant homologies between corresponding normal 5' and 3' regions flanking the breakpoint of the patient, so a nonhomologous recombination is the most possible mechanism for this 25-kb deletion. The analysis also reveals that the patient has a novel 30-bp duplication in the 5' flanking region of the deletion point, which was transmitted by his mother with the deletion. Furthermore we suggest that the deletion occurred in his grandfather.
我们克隆并鉴定了一个基因组DNA片段，该片段包含一名慢性肉芽肿病患者的缺失连接点，其25kb的缺失延伸至CYBB基因5'端的三分之二区域。该缺失的3'断点位于CYBB基因的第7外显子。在正常人中，一个LINE-1元件位于CYBB基因上游5kb处，而该患者缺失的5'断点就在该LINE-1元件中。患者断点两侧相应的正常5'和3'区域之间没有明显的同源性，因此非同源重组是导致这25kb缺失的最可能机制。分析还显示，该患者在缺失点的5'侧翼区域有一个新的30bp重复序列，该重复序列由其携带缺失的母亲遗传而来。此外，我们推测该缺失发生在他的祖父身上。
