De Novo Variants Disturbing the Transactivation Capacity of POU3F3 Cause a Characteristic Neurodevelopmental Disorder
De Novo Variants Disturbing the Transactivation Capacity of POU3F3 Cause a Characteristic Neurodevelopmental Disorder
复制标题
破坏POU3F3转录激活能力的新生变异导致一种特征性神经发育障碍
DOI：
10.1016/j.ajhg.2019.06.007
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发表时间：
2019-08-01
影响因子：
9.8
通讯作者：
Fisher, Simon E.
中科院分区：
文献类型：
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作者：
Blok, Lot Snijders;Kleefstra, Tjitske;Fisher, Simon E.
POU3F3，也称为 Brain-1，是一种众所周知的参与中枢神经系统发育的转录因子，但此前并未发现它与神经发育障碍有关。在这里，我们报告了 19 名具有杂合 POU3F3 破坏的个体的鉴定，其中大多数是新生变异。所有个体都有发育迟缓和/或智力障碍以及言语和语言技能障碍。十三个人具有特征性的低位、突出和/或杯状耳朵。十一份 MRI 报告中有七份观察到大脑异常。 POU3F3 是一种无内含子基因，对无义介导的衰变不敏感，13 个个体携带蛋白质截短变体。我们在细胞模型中测试的所有截短变体都会导致编码蛋白的异常亚细胞定位。荧光素酶测定证明这些等位基因对具有 FOXP2 衍生结合基序的报告基因的转录激活有负面影响。除了功能缺失变异之外，五个个体还具有错义变异，这些变异聚集在功能域内的特定位置，并鉴定出一个小的框内缺失。在我们的检测中，两种错义变体显示反式激活能力降低，而一种变体则显示出功能获得效应，表明一种独特的病理生理学机制。在生物发光共振能量转移 (BRET) 相互作用测定中，我们测试的所有截短 POU3F3 版本的二聚化能力均显着受损，而所有错义变体均显示与野生型 POU3F3 的二聚化不受影响。总而言之，我们对 POU3F3 致病变异的鉴定和基于功能细胞的分析，再加上临床特征，表明该基因的破坏与特征性神经发育障碍有关。
POU3F3, also referred to as Brain-1, is a well-known transcription factor involved in the development of the central nervous system, but it has not previously been associated with a neurodevelopmental disorder. Here, we report the identification of 19 individuals with heterozygous POU3F3 disruptions, most of which are de novo variants. All individuals had developmental delays and/or intellectual disability and impairments in speech and language skills. Thirteen individuals had characteristic low-set, prominent, and/or cupped ears. Brain abnormalities were observed in seven of eleven MRI reports. POU3F3 is an intronless gene, insensitive to nonsense-mediated decay, and 13 individuals carried protein-truncating variants. All truncating variants that we tested in cellular models led to aberrant subcellular localization of the encoded protein. Luciferase assays demonstrated negative effects of these alleles on transcriptional activation of a reporter with a FOXP2-derived binding motif. In addition to the loss-of-function variants, five individuals had missense variants that clustered at specific positions within the functional domains, and one small in-frame deletion was identified. Two missense variants showed reduced transactivation capacity in our assays, whereas one variant displayed gain-of-function effects, suggesting a distinct pathophysiological mechanism. In bioluminescence resonance energy transfer (BRET) interaction assays, all the truncated POU3F3 versions that we tested had significantly impaired dimerization capacities, whereas all missense variants showed unaffected dimerization with wild-type POU3F3. Taken together, our identification and functional cell-based analyses of pathogenic variants in POU3F3, coupled with a clinical characterization, implicate disruptions of this gene in a characteristic neurodevelopmental disorder.