Treacher Collins syndrome (TCS) is a heterogenous malformation syndrome characterized by a distinct facial appearance including downslanting palpebral fissures, malar hypoplasia, conductive hearing loss, and mandibular hypoplasia. Recently, a new causative gene, POLR1B, encoding DNA-directed RNA polymerase I subunit RPA2, was identified as a fourth type of TCS (TCS4). We describe another patient with TCS4 caused by a recurrent POLR1B variant, c.3007C#x3e;T; p.Arg1003Cys. Including our patient, all 4 patients with p.(Arg1003Cys) had atresia of the external auditory canal and microtia. All of the reported pathogenic variants in POLR1B were clustered at only 2 residues. Our patient highlights the genotype-phenotype correlation in TCS4 associated with POLR1B.
Mol Syndromol

中文翻译：

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POLR1B 中的循环变体，c.3007C>T；p.Arg1003Cys，与 Treacher Collins 综合征 4 型的外管闭锁和小耳畸形有关

Treacher Collins 综合征 (TCS) 是一种异质性畸形综合征，其特征在于独特的面部外观，包括下斜睑裂、颧骨发育不全、传导性听力损失和下颌骨发育不全。最近，一种新的致病基因POLR1B，编码 DNA 指导的 RNA 聚合酶 I 亚基 RPA2，被鉴定为第四类 TCS (TCS4)。我们描述了另一名由复发性POLR1B变异引起的 TCS4 患者，c.3007C#x3e;T; p.Arg1003Cys。包括我们的患者在内，所有 4 名 p.(Arg1003Cys) 患者都有外耳道闭锁和小耳畸形。POLR1B中所有报告的致病变异仅聚集在 2 个残基处。我们的患者强调了 TCS4 中的基因型-表型相关性POLR1B。
摩尔综合征