Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China.
Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.
Parkinsonism Relat Disord. 2019 May;62:128-133. doi: 10.1016/j.parkreldis.2019.01.001. Epub 2019 Jan 2.
Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism due to ATP7B pathogenic mutations. Disease manifestations can be prevented if early diagnosis and effective treatment are given. Direct sequencing is routinely used to confirm WD diagnosis, but cannot identify gross rearrangements.
Sanger sequencing of ATP7B was performed in 142 newly recruited WD index patients. The clinical effects of identified variants were classified according to American College of Medical Genetics and Genomics (ACMG) standards and guidelines. Multiplex ligation-dependent probe amplification (MLPA) was performed in 168 WD cases with clinical WD unexplained by Sanger sequencing, selected from our total case series of 774 WD patients. After identifying gross rearrangements within ATP7B, the breakpoints were determined by long-range PCR and direct sequencing.
In the 142 WD patients, we identified 71 sequence alterations in ATP7B, of which 15 were novel; 14 of these were classified as 'pathogenic' or 'likely pathogenic', including 2 intronic variants affecting splice sites. In 6 of 168 WD patients, MLPA identified four heterozygous gross ATP7B deletions. One was a whole gene deletion, and three were intragenic deletions which were mapped to breakpoint locations, revealing non-homologous end joining.
Intragenic deletions are responsible for WD and non-homologous end joining could be the pathogenesis, therefore the detection of intragenic deletions should be included in comprehensive genetic testing for WD.
威尔逊病（WD）是一种由于 ATP7B 致病突变导致的铜代谢常染色体隐性遗传病。如果能早期诊断和有效治疗，就能预防疾病的发生。直接测序通常用于确认 WD 的诊断，但无法识别大片段重排。
对 142 例新招募的 WD 指数患者进行 ATP7B 的 Sanger 测序。根据美国医学遗传学与基因组学学会（ACMG）标准和指南，对鉴定出的变异体的临床影响进行分类。对我们 774 例 WD 患者的总病例系列中，经 Sanger 测序无法解释的 168 例 WD 病例进行多重连接依赖性探针扩增（MLPA）检测。在鉴定 ATP7B 内的大片段重排后，通过长距离 PCR 和直接测序确定断点。
在 142 例 WD 患者中，我们在 ATP7B 中发现了 71 种序列改变，其中 15 种是新的；其中 14 种被归类为“致病性”或“可能致病性”，包括 2 种影响剪接位点的内含子变异。在 168 例 WD 患者中的 6 例中，MLPA 发现了 4 种杂合的 ATP7B 大片段缺失。其中 1 种是全基因缺失，3 种是基因内缺失，这些缺失被定位到断点位置，显示出非同源末端连接。
基因内缺失是 WD 的原因，非同源末端连接可能是其发病机制，因此，基因内缺失的检测应纳入 WD 的综合基因检测中。
