Mutations in genes encoding subunits of RNA polymerases I and III cause Treacher Collins syndrome

Johannes Dauwerse and colleagues report the identification of mutations in the genes encoding subunits of RNA polymerases I and III, which are involved in transcription of rRNA and tRNA, in individuals with Treacher Collins syndrome. These findings support the hypothesis that TCS is a ribosomopathy. We identified a deletion of a gene encoding a subunit of RNA polymerases I and III, POLR1D , in an individual with Treacher Collins syndrome (TCS). Subsequently, we detected 20 additional heterozygous mutations of POLR1D in 252 individuals with TCS. Furthermore, we discovered mutations in both alleles of POLR1C in three individuals with TCS. These findings identify two additional genes involved in TCS, confirm the genetic heterogeneity of TCS and support the hypothesis that TCS is a ribosomopathy.