Molecular Characterisation of Treacher Collins Syndrome in a South African Cohort: Novel Disease‐Causing Variants in TCOF1 and POLR1D
Treacher Collins syndrome (TCS) is a rare craniofacial disorder characterised by variable expressivity. It is caused by pathogenic variants in the TCOF1, POLR1D, POLR1C, or POLR1B genes. Common clinical features include hypoplasia of the zygomatic complex and mandible, downward‐slanting palpebral fissures, lower eyelid...