BRF1 and Cerebellar-facial-dental syndrome: Interestingly, although not technically a part of POLR3-related disorders, mutations in BRF1, encoding a subunit of the Pol III transcription factor TFIIIB-β, cause a cerebellar-facial-dental syndrome with clinical overlap with POLR3-related disorders (Borck et al., 2015; Jee et al., 2017), emphasizing the vulnerability of these tissues to Pol III dysfunction.