title: In-Frame Deletion and Missense Mutations of the C-Terminal Helicase Domain of SMARCA2 in Three Patients with Nicolaides-Baraitser Syndrome.
abstract: Using high-resolution molecular karyotyping with SNP arrays to identify candidate genes for etiologically unexplained intellectual disability, we identified a 32-kb de novo in-frame deletion of the C-terminal helicase domain of the SMARCA2 gene in a patient with severe intellectual disability, epilepsy, sparse hair, prominent joints, and distinct facial anomalies. Sequencing of the gene in patients with a similar phenotype revealed de novo missense mutations in this domain in 2 further patients, pointing to a crucial role of the SMARCA2 C-terminal helicase domain. The clinical features observed in all 3 patients are typical of Nicolaides-Baraitser syndrome, an only rarely reported syndrome with mainly moderate to severe intellectual disability. Notably, one of our patients with a p.Gly1132Asp mutation showed typical morphological features but an exceptional good development with borderline overall IQ and learning difficulties, thus expanding the phenotypic spectrum of Nicolaides-Baraitser syndrome.
authors: Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
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authors: Wolff
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authors: Endele
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authors: Azzarello-Burri
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authors: Hoyer
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authors: Zweier
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