Abstract
Treacher Collins syndrome (TCS) is a frequent cause of mandibulofacial dysostosis.To date, TCS-causing mutations in three genes, namely TCOF1, POLR1D, and POLR1Chave been identified. TCS is usually inherited in an autosomal dominant manner, witha high clinical variability and no phenotype–genotype correlation. Up-to now, fivefamilies have been reported with an autosomal recessive mode of inheritance due tomutations in POLR1D or POLR1C. We report here a new family with two sistersaffected by mild TCS carrying compound POLR1C heterozygous mutations, andreview the literature on mild forms of TCS, autosomal recessive inheritance in thissyndrome and POLR1C mutations.