Identification of a novel gross deletion of TCOF1 in a Chinese prenatal case with Treacher Collins syndrome.

Background: Treacher Collins syndrome (TCS) is the most common mandibulofacial dysostosis with an autosomal dominant or rarely recessive manner of inheritance. It is still challenging to make a definite diagnosis for affected fetuses with TCS only depending on the ultrasound screening. Genetic tests can contribute to the accurate diagnosis for those prenatal cases. Methods: Targeted exome sequencing was performed in a fetus of a Chinese family, who presenting an abnormal facial appearance by prenatal 2D and 3D ultrasound screening, including micrognathia, nasal bridge pit, and abnormal auricle. The result was validated with multiplex ligation-dependent probe amplification (MLPA) and real-time quantitative PCR (qPCR). Results: A novel 2-6 exons deletion ofTCOF1gene was identified and confirmed by the MLPA and qPCR in the fetus, which was inherited from the affected father with similar facial anomalies. Conclusion: The heterozygous deletion of 2-6 exons inTCOF1results in the TCS of this Chinese family. Our findings not only enlarge the spectrum of mutations inTCOF1gene, but also highlight the values of combination of ultrasound and genetics tests in diagnosis of craniofacial malformation-related diseases during perinatal period.