Differential DNA methylation of the D4Z4 repeat in patients with FSHD and asymptomatic carriers
Differential DNA methylation of the D4Z4 repeat in patients with FSHD and asymptomatic carriers
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DOI：
10.1212/wnl.0000000000000708
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发表时间：
2014-08-19
期刊：
影响因子：
9.9
通讯作者：
Magdinier, Frederique
中科院分区：
文献类型：
--
作者：
Gaillard, Marie-Cecile;Roche, Stephane;Magdinier, Frederique
目的：探讨DNA低甲基化与面肩肩关节营养不良(FSHD)患者临床外显性的关系。方法：采用DNA甲基化免疫沉淀法和亚硫酸氢钠测序法，对95例FSHD患者(37例FSHD1、29例D4Z4基因缩短的无症状者、9例FSHD2患者和20例对照组)的临床外显性进行了研究。结果：两种方法在无症状携带者或对照组与临床FSHD患者之间存在显著差异，尤其是在重复序列的近端。在无症状携带者中缺乏临床表达与甲基化水平类似于对照。结论：我们提供了一个概念证明，我们描述的靶向方法可以系统地应用于常规诊断中的患者样本，并提示D4Z4中的局部低甲基化可能作为FSHD表型临床表达的修饰物。证据分类：这项研究提供了III类证据，证明D4Z4区域低甲基化检测准确地区分了FSHD患者和D4Z4收缩而没有FSHD的患者。
Objective: We investigated the link between DNA hypomethylation and clinical penetrance in facioscapulohumeral dystrophy (FSHD) because hypomethylation is moderate and heterogeneous in patients and could not thus far be correlated with disease presence or severity.Methods: To investigate the link between clinical signs of FSHD and DNA methylation, we explored 95 cases (37 FSHD1, 29 asymptomatic individuals carrying a shortened D4Z4 array, 9 patients with FSHD2, and 20 controls) by implementing 2 approaches: methylated DNA immunoprecipitation and sodium bisulfite sequencing.Results: Both methods revealed statistically significant differences between asymptomatic carriers or controls and individuals with clinical FSHD, especially in the proximal region of the repeat. Absence of clinical expression in asymptomatic carriers is associated with a level of methylation similar to controls.Conclusions: We provide a proof of concept that the targeted approaches that we describe could be applied systematically to patient samples in routine diagnosis and suggest that local hypomethylation within D4Z4 might serve as a modifier for clinical expression of FSHD phenotype. Classification of evidence: This study provides Class III evidence that assays for hypomethylation within the D4Z4 region accurately distinguish patients with FSHD from individuals with D4Z4 contraction without FSHD.