The University of Chicago Genetic Services Laboratories has been offering diagnostic testing for Cornelia de Lange syndrome since 2006, and has developed considerable expertise in molecular testing for this condition. In recent years somatic mosaicism has been increasingly recognized in patients with Cornelia de Lange syndrome (Huisman et al., 2013; Nizon et al., 2016), and in some patients mosaic pathogenic variants may be detected in DNA extracted from buccal samples but not detectable in DNA derived from a blood sample.

In order to improve the molecular diagnostic testing options for CdLS, we have validated a Next Generation Sequencing assay that is able to detect mosaic sequence variants present at levels of 10% or higher. We recommend testing on buccal samples, rather than blood or saliva samples, to enhance the detection of mosaic variants. 

Starting September 18, 2017, all patients referred for our Cornelia de Lange Syndrome Panel or single gene sequence analysis for NIPBL, SMC1A, SMC3, HDAC8 and RAD21 will automatically be processed on our assay designed for mosaicism detection. Please contact us for more information about our CdLS testing options.