A Chinese family with Axenfeld-Rieger syndrome: report of the clinical and genetic findings

作者:Sun, Da-Peng; Dai, Yun-Hai; Pan, Xiao-Jing; Shan, Tao; Wang, Dian-Qiang*; Chen, Peng*
来源:International Journal of Ophthalmology, 2017, 10(6): 847-853.
DOI:10.18240/ijo.2017.06.04

摘要

AIM: To describe a Chinese family affected by a severe form of Axenfeld-Rieger syndrome (ARS) and characterize the molecular defect in PITX2 in the family. METHODS: Patients presented with typical ARS from a Chinese family were investigated. We performed genome-wide linkage scan and exome sequencing to identify the pathogenic mutations. Candidate mutations were verified for co-segregation in the whole pedigree using Sanger sequencing. Real-time polymerase chain reaction (RTPCR) and Western blotting were performed to verify the expression of the pathogenic gene. RESULTS: Genome-wide linkage and exome sequencing analyses showed PITX2 as the disease candidate gene. A>G substitution at position -11 of 3'ss of exon 5 (IVS5-11A>G) that co-segregated with the disease phenotype was discovered in the family. The PITX2 messenger ribonucleic acid and protein levels were about 50% lower in patients with ARS than in unaffected family members in the family. CONCLUSION: Our findings implicate the first intronic mutation of the PITX2 gene in the pathogenesis of a severe form of ARS in a Chinese family. This study highlights the importance of a systematic search for intronic mutation in ARS cases for which no mutations in the exons of PITX2 have been found.

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