GENETIC & MOLECULAR STUDIES IN LOWE'S SYNDROME

LOWE眼小脑肾综合征(LOCRS)是一种X连锁基因 病因不明的先天代谢错误。受影响的男性 发育迟缓，有先天性白内障和肾小管 功能障碍。携带者女性经常表现出晶状体混浊 可能有助于杂合子检测，但不是完全敏感或 具体的。产前诊断是不可能的。LOCRS的轨迹 已通过与限制性内切酶的连锁被映射到Xq25区域 Xq24-26基因的片段长度多态(RFLP) 1例X/3易位的女性患者发生LOCRS Xq25处的断点。 该项目将分两个阶段进行： 阶段1：我们建议使用X；3易位细胞系 产生Der X和Der 3的体细胞杂交 从正常的X分离出来。这些混血儿将允许我们 从Xq24-26区域定位一组独立的粘粒克隆 关于Xq25断点。宇宙飞船的侧翼 断点将用于按顺序搜索多个RFLP 为LOCRS生成信息量很大的侧翼标记。 这些RFLP将被测试与LOCRS的链接，每组6个 隔离这种疾病的家庭。如果看到重组 有了一个特殊的侧翼宇宙彗星，额外的宇宙星将是 分析RFLP，直到一对紧密连锁的侧翼标记 已被确认。 第二阶段：LOCRS基因座和LCRS基因之间的分子距离 Xq24-26粘粒序列将在两个不同的 方式。第一，来自X；3的大限制性片段 易位系和含有derx或der3的杂交种将是 脉冲场凝胶电泳法分离和探针 寻找异常片段的Xq24-26粘粒序列 由断点引起。500 kb范围内的宇宙流星体 很可能在大于50的集合中找到断点 即将推出的宇宙飞船克隆体。第二，一组DNA 来自41名患有LOCRS的独立患者将接受筛查 这些相同的Xq24-26宇宙体来寻找间隙缺失 影响了LOCRS。内的粘粒序列的鉴定 LOCRS基因座的可测量分子距离是 朝着基因分离迈出的重要的第一步。

The oculocerebrorenal syndrome of Lowe (LOCRS) is an X-linked inborn error of metabolism of unknown etiology. Affected males are retarded and have congenital cataracts and renal tubular dysfunction. Carrier females frequently show lens opacities that may aid in heterozygote detection but are not fully sensitive or specific. Prenatal diagnosis is not possible. The locus for LOCRS has been mapped to the Xq25 region by linkage to restriction fragment length polymorphisms (RFLPs) in Xq24-26 and by the occurrence of LOCRS in a female with an X/3 translocation with breakpoint at Xq25. The project will be carried out in two phases: Phase 1: We propose to use the X;3 translocation cell line to generate somatic cell hybrids in which the der X and der 3 are isolated away from the normal X. These hybrids will allow us to map a set of independent cosmid clones from the Xq24-26 region with respect to the Xq25 breakpoint. Cosmids that flank the breakpoint will be used to search for a number of RFLPs in order to generate highly informative flanking markers for LOCRS. These RFLPS will be tested for linkage to LOCRS in a set of 6 families segregating for the disease. If recombination is seen with a particular flanking cosmid, additional cosmids will be analyzed for RFLPs until a pair of tightly linked flanking markers is identified. Phase 2: The molecular distance between the LOCRS locus and the Xq24-26 cosmid sequences will be estimated in two different ways. First, large restriction fragments from the X;3 translocation line and the hybrids containing derX or der3 will be separated by pulsed-field gel electrophoresis and probed with Xq24-26 cosmid sequences to look for an aberrant fragment cuased by the breakpoint. A cosmid within 500 kb of the breakpoint is likely to be found among the set of greater than 50 cosmid clones that will be available. Second, a panel of DNA from 41 independent patients with LOCRS will be screened with these same Xq24-26 cosmids to look for an interstitial deletion affecting the LOCRS. Identification of a cosmid sequence within a measurable molecular distance of the LOCRS locus is an important first step towards gene isolation.