Identification of a novel gross deletion ofTCOF1in a Chinese prenatal case with Treacher Collins syndrome
MOLECULAR GENETICS & GENOMIC MEDICINE
Authors: Liu, Jing; Lin, Pengsiyuan; Pang, Jialun; Jia, Zhengjun; Peng, Ying; Xi, Hui; Wu, Lingqian; Li, Zhuo; Wang, Hua
Abstract
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.
Chronic intestinal pseudo-obstruction in a child with Treacher Collins syndrome
ARCHIVES DE PEDIATRIE
Authors: Giabicani, E.; Lemale, J.; Dainese, L.; Boudjemaa, S.; Coulomb, A.; Tounian, P.; Dubern, B.
Abstract
Background. Treacher Collins syndrome (TCS) mainly presents with severe craniofacial developmental abnormalities characterized by a combination of bilateral downward-slanting palpebral fissures, colobotnas of the lower eyelids, hypoplasia of the facial bones, cleft palate, malformation of the external ears, atresia of the external auditory canals, and bilateral conductive hearing loss. It is due to mutations in Treacher Collins syndrome 1 (TCOF1) (5q32-q33.1) and Polymerase RNA 1 polypeptides D and C (POLR1D [13q12.2], and POLR1 C [6p21.1]) genes, which are responsible for increased neuroepithelial apoptosis during embryogenesis resulting in the lack of neural crest cells involved in facial bone and cartilage formation. Altered function of the upper digestive tract has been reported, whereas severe dysmotility disorders have never been reported. We describe here the first case of TCS associated with histologically proven chronic intestinal pseudo -obstruction (CIPO) in humans. Case presentatios A 12-year-old boy with TCS due to TCOF1 gene deletion experienced nutritional difficulties and digestive intolerance from birth. CIPO was suspected during childhood because of severe intestinal dysmotility leading to enteral-jejunal nutrition intolerance and dependence on total parenteral nutrition. Diagnosis of CIPO with nervous abnormalities was histologically confirmed on a surgical rectal biopsy that showed enlarged ganglionic myenteric plexus. At the age of 9 years, an isolated colonic stenosis without dilatation responsible for severe abdominal pain and altered quality of life led to digestive derivation contributing to rapid disappearance of chronic abdominal pain. At the age of 12 years, the patient was still dependent on total home parenteral nutrition 7 days a week to maintain regular growth velocity. Conclusion. Recently, mice studies have pointed out the role played by TCOF1 in ganglionic cell migration in the foregut, suggesting that the synergistic haploinsufficiency of Tcof1 and Pax3, a transcription factor regulating the RET gene involved in disorders of neural crest cell development, probably results in colonic aganglionosis and may explain the association described here between TCS and CIPO. This case may correspond to this possible mechanism in humans. These findings and our clinical report suggest that CIPO may be assessed as unusual digestive manifestations in TCS with TCOF1 deletion. (C) 2017 Published by Elsevier Masson SAS.