Global transcriptional disturbances underlie Cornelia de Lange syndrome and related phenotypes

• Text
• PDF

Abstract

Cornelia de Lange syndrome (CdLS) is a genetically heterogeneous disorder that presents with extensive phenotypic variability, including facial dysmorphism, developmental delay/intellectual disability (DD/ID), abnormal extremities, and hirsutism. About 65% of patients harbor mutations in genes that encode subunits or regulators of the cohesin complex, including NIPBL, SMC1A, SMC3, RAD21, and HDAC8. Wiedemann-Steiner syndrome (WDSTS), which shares CdLS phenotypic features, is caused by mutations in lysine-specific methyltransferase 2A (KMT2A). Here, we performed whole-exome sequencing (WES) of 2 male siblings clinically diagnosed with WDSTS; this revealed a hemizygous, missense mutation in SMC1A that was predicted to be deleterious. Extensive clinical evaluation and WES of 32 Turkish patients clinically diagnosed with CdLS revealed the presence of a de novo heterozygous nonsense KMT2A mutation in 1 patient without characteristic WDSTS features. We also identified de novo heterozygous mutations in SMC3 or SMC1A that affected RNA splicing in 2 independent patients with combined CdLS and WDSTS features. Furthermore, in families from 2 separate world populations segregating an autosomal-recessive disorder with CdLS-like features, we identified homozygous mutations in TAF6, which encodes a core transcriptional regulatory pathway component. Together, our data, along with recent transcriptome studies, suggest that CdLS and related phenotypes may be “transcriptomopathies” rather than cohesinopathies.

Authors

Bo Yuan, Davut Pehlivan, Ender Karaca, Nisha Patel, Wu-Lin Charng, Tomasz Gambin, Claudia Gonzaga-Jauregui, V. Reid Sutton, Gozde Yesil, Sevcan Tug Bozdogan, Tulay Tos, Asuman Koparir, Erkan Koparir, Christine R. Beck, Shen Gu, Huseyin Aslan, Ozge Ozalp Yuregir, Khalid Al Rubeaan, Dhekra Alnaqeb, Muneera J. Alshammari, Yavuz Bayram, Mehmed M. Atik, Hatip Aydin, B. Bilge Geckinli, Mehmet Seven, Hakan Ulucan, Elif Fenercioglu, Mustafa Ozen, Shalini Jhangiani, Donna M. Muzny, Eric Boerwinkle, Beyhan Tuysuz, Fowzan S. Alkuraya, Richard A. Gibbs, James R. Lupski