Zhang Qiang, Guo Xiaohong, Tian Tian, Wang Teng, Li Qiaoli, Wang Lei, Liu Yun, Xing Qinghe, He Lin, Zhao Xinzhi
Children Hospital of Fudan University, Shanghai, China; Shanghai Key Laboratory of Prevention and Intervention of Birth Defects, Shanghai, China; Shanghai Center for Women and Children's Health, China.
Children Hospital of Fudan University, Shanghai, China; Shanghai Key Laboratory of Prevention and Intervention of Birth Defects, Shanghai, China.
Clin Chim Acta. 2017 May;468:174-179. doi: 10.1016/j.cca.2017.03.008. Epub 2017 Mar 8.
Early diagnosis of Turner syndrome (TS) may improve preventive measures and treatment. X-chromosome inactivation specific differentially methylated CpG sites (XIDMSs) that are high methylated in inactive X chromosomes (Xi) and unmethylated in active X chromosomes (Xa) may be potential makers for TS detection.
The candidate XIDMSs were screened from 9 male and 12 female DNA samples with normal karyotypes using the Illumina 450k array and validated by bisulfite sequencing PCR and pyrosequencing assay. X chromosome dosage was calculated according to the methylation level of multiple XIDMSs.
Overall, 108 candidate XIDMSs were screened by the 450k array. Validations indicated that XIDMSs gathered and formed the X-chromosome inactivation specific differentially methylated regions (XIDMRs). Using 3 XIDMRs at SAT1, UXT and UTP14A loci, 36 TS, 22 normal female and 6 male samples were analyzed. Methylation levels of the 20 XIDMSs in the XIDMRs could distinguish between TS and normal female DNA samples, the X chromosome dosage was consistent with karyotyping data. Analyzing samples of 2 triple X syndrome and 3 Klinefelter syndrome patients suggested that this method could be used to detect X chromosome aneuploids other than TS.
XIDMSs are widely spread along the X chromosome and might be effective markers for detection of TS and other X chromosome aneuploids.
特纳综合征（TS）的早期诊断可能会改善预防措施和治疗效果。X染色体失活特异性差异甲基化CpG位点（XIDMSs）在失活的X染色体（Xi）中高度甲基化，而在活跃的X染色体（Xa）中未甲基化，可能是TS检测的潜在标志物。
使用Illumina 450k芯片从9例核型正常的男性和12例核型正常的女性DNA样本中筛选候选XIDMSs，并通过亚硫酸氢盐测序PCR和焦磷酸测序分析进行验证。根据多个XIDMSs的甲基化水平计算X染色体剂量。
总体而言，通过450k芯片筛选出108个候选XIDMSs。验证表明，XIDMSs聚集并形成了X染色体失活特异性差异甲基化区域（XIDMRs）。使用位于SAT1、UXT和UTP14A基因座的3个XIDMRs，对36例TS、22例正常女性和6例男性样本进行了分析。XIDMRs中20个XIDMSs的甲基化水平可以区分TS和正常女性DNA样本，X染色体剂量与核型分析数据一致。对2例XXX综合征和3例克氏综合征患者的样本分析表明，该方法可用于检测除TS以外的X染色体非整倍体。
XIDMSs广泛分布于X染色体上，可能是检测TS和其他X染色体非整倍体的有效标志物。
