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A Recurrent Variant in <b><i>POLR1B</i></b>, c.3007C&#x3e;T; p.Arg1003Cys, Associated with Atresia of the External Canal and Microtia in Treacher Collins Syndrome Type 4

2021; Karger Publishers; Volume: 12; Issue: 2 Linguagem: Inglês

10.1159/000513224

1661-8777

Yumi Enomoto, Yoshinori Tsurusaki, Makiko Tominaga, Shinji Kobayashi, Maki Inoue, Kazutoshi Fujita, Tatsuro Kumaki, Hiroaki Murakami, Kenji Kurosawa,

Head and Neck Surgical Oncology

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, <i>POLR1B</i>, 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 <i>POLR1B</i> 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 <i>POLR1B</i> were clustered at only 2 residues. Our patient highlights the genotype-phenotype correlation in TCS4 associated with <i>POLR1B</i>.