Gorlin J B
Memorial Blood Centers of Minnesota, Minneapolis 55404-3789, USA.
J Pediatr Hematol Oncol. 1998 Mar-Apr;20(2):112-9. doi: 10.1097/00043426-199803000-00005.
The majority of known female carriers of X-linked chronic granulomatous disease (X-CGD), a deficiency of the gp91-phox (phagocyte oxidase) subunit and the most common genetic subtype of CGD, are not informative for the linked restriction fragment length polymorphisms (RFLPs) described to date. The isolation and characterization of two polymorphic (CA/GT)n repeats that lie within the X-CGD gene are reported, which are a useful linked marker for prenatal diagnosis.
cDNA for gp91-phox was used to probe a genomic library. Genomic clones were isolated and screened for (CA/GT)n repeats. The repeats were isolated and sequences surrounding the repeats were determined. Oligonucleotide primer pairs surrounding the repeats were chosen to facilitate polymerase chain reaction (PCR) across the repeat.
Analysis of DNA derived from over 100 individuals shows both markers to be highly polymorphic with a resultant high proportion of heterozygosity in females. Several kindreds affected by X-CGD were studied and the (CA/GT)n length polymorphisms were shown to segregate with the clinical syndrome or biochemical carrier status. The technique was prospectively applied to several kindreds containing a carrier mother and an affected child. In a case where a male fetus was shown to carry the unaffected allele, the pregnancy was carried to term and the child was not affected.
This approach is highly informative in a multiple allele system, can provide a technical analysis in just hours, requires only a ng of DNA, and permits the transport of diagnostic samples. Therefore, this method can be used early in pregnancy on a chorionic villus biopsy sample for prenatal diagnosis.
X连锁慢性肉芽肿病（X-CGD）是一种因gp91-吞噬氧化酶（吞噬细胞氧化酶）亚基缺乏所致的疾病，也是慢性肉芽肿病最常见的遗传亚型。大多数已知的X-CGD女性携带者对于迄今所描述的连锁限制性片段长度多态性（RFLP）而言并无信息价值。本文报道了位于X-CGD基因内的两个多态性（CA/GT）n重复序列的分离与鉴定，它们是产前诊断的有用连锁标记。
用gp91-吞噬氧化酶的cDNA探测基因组文库。分离基因组克隆并筛选（CA/GT）n重复序列。分离这些重复序列并测定其周围的序列。选择围绕重复序列的寡核苷酸引物对以便于通过重复序列进行聚合酶链反应（PCR）。
对来自100多个个体的DNA分析表明，这两个标记均具有高度多态性，导致女性中杂合子比例很高。对几个受X-CGD影响的家系进行了研究，结果显示（CA/GT）n长度多态性与临床综合征或生化携带者状态共分离。该技术被前瞻性地应用于几个有携带者母亲和患病孩子的家系。在一例男性胎儿被证明携带未受影响等位基因的病例中，妊娠足月，孩子未受影响。
这种方法在多等位基因系统中具有很高的信息价值，只需数小时即可提供技术分析，仅需纳克级的DNA，并允许运输诊断样本。因此，这种方法可在妊娠早期用于绒毛膜绒毛活检样本的产前诊断。
