Shapiro L J, Yen P, Pomerantz D, Martin E, Rolewic L, Mohandas T
Howard Hughes Medical Institute Laboratories, University of California, Los Angeles.
Proc Natl Acad Sci U S A. 1989 Nov;86(21):8477-81. doi: 10.1073/pnas.86.21.8477.
The human steroid sulfatase gene (STS) is located on the distal X chromosome short arm close to the pseudoautosomal region but in a segment of DNA that is unique to the X chromosome. In contrast to most X chromosome-encoded genes, STS expression is not extinguished during the process of X chromosome inactivation. Deficiency of STS (steryl-sulfatase; steryl-sulfate sulfohydrolase, EC 3.1.6.2) activity produces the syndrome of X chromosome-linked ichthyosis, which is one of the most common inborn errors of metabolism in man. Approximately 90% of STS- individuals have large deletions at the STS locus. We and others have found that the end points of such deletions are heterogeneous in their location. One recently ascertained subject was observed to have a 40-kilobase deletion that is entirely intragenic, permitting the cloning and sequencing of the deletion junction. Studies of this patient and of other X chromosome sequences in other subjects permit some insight into the mechanism(s) responsible for generating frequent deletions on the short arm of the X chromosome.
人类类固醇硫酸酯酶基因（STS）位于X染色体短臂远端，靠近假常染色体区域，但位于X染色体特有的一段DNA中。与大多数X染色体编码的基因不同，STS的表达在X染色体失活过程中不会熄灭。STS（甾醇硫酸酯酶；甾醇硫酸酯硫酸水解酶，EC 3.1.6.2）活性的缺乏会导致X染色体连锁鱼鳞病综合征，这是人类最常见的先天性代谢缺陷之一。大约90%的STS缺陷个体在STS基因座处有大片段缺失。我们和其他人发现，这些缺失的端点在位置上是异质的。最近确定的一名受试者被观察到有一个40千碱基的缺失，该缺失完全在基因内，这使得能够对缺失连接处进行克隆和测序。对该患者以及其他受试者中其他X染色体序列的研究，有助于深入了解导致X染色体短臂频繁发生缺失的机制。
