Fritz B, Küster W, Orstavik K H, Naumova A, Spranger J, Rehder H
Department of Clinical Genetics, Medical Center of Human Genetics, Philipps University Marburg, Germany.
Hum Genet. 1998 Oct;103(4):441-9. doi: 10.1007/s004390050848.
We report on a female with mental and motor retardation, facial dysmorphism, abnormal pigmentation reminiscent to hypomelanosis of Ito (HI), and karyotypic mosaicism involving a small supernumerary marker chromosome. The marker chromosome was defined by fluorescence in situ hybridisation (FISH) as a ring X chromosome with breakpoints in the juxtacentromeric region. FISH analysis showed that the ring does not include the XIST locus at the X-inactivation centre and, therefore, may not be subject to X inactivation. X-inactivation studies with the HUMARA (human androgen receptor) and FMR1 assay showed a skewed X-inactivation pattern (85:15) with preferential inactivation of the paternal X chromosome. These results are discussed with respect to the role of functional disomy of Xp in the pathogenesis of HI.
我们报告了一名患有智力和运动发育迟缓、面部畸形、类似伊藤色素减退症（HI）的异常色素沉着以及涉及一条小的额外标记染色体的核型嵌合体的女性。通过荧光原位杂交（FISH）将该标记染色体确定为一条在近着丝粒区域有断点的环状X染色体。FISH分析表明该环不包括X染色体失活中心的XIST基因座，因此可能不受X染色体失活的影响。使用HUMARA（人类雄激素受体）和FMR1检测进行的X染色体失活研究显示出偏态的X染色体失活模式（85:15），父本X染色体优先失活。针对Xp功能二体性在HI发病机制中的作用对这些结果进行了讨论。
