Patients carrying 9q31.1-q32 deletion share common features with Cornelia de Lange Syndrome.

BACKGROUND Cornelia de Lange Syndrome (CdLS) is a rare but severe clinically heterogeneous developmental disorder characterized by facial dysmorphia, growth and cognitive retardation, and abnormalities of limb development. OBJECTIVES To determine the pathogenesis of a patient with CdLS. METHODS We studied a patient with CdLS by whole exome sequencing, karyotyping and Agilent CGH Array. The results were confirmed by quantitative real-time PCR analysis of the patient and her parents. Further comparison of our patient and cases with partially overlapping deletions retrieved from the literature and databases was undertaken. RESULTS Whole exome sequencing had excluded the mutation of cohesion genes such as NIPBL,SMC1A and SMC3. The result of karyotyping showed a deletion of chromosome 9q31.1-q32 and the result of Agilent CGH Array further displayed a 12.01-Mb region of deletion at chromosome bands 9q31.1-q32. Reported cases with the deletion of 9q31.1-q32 share similar features with our CdLS patient. One of the genes in the deleted region, SMC2, belongs to the Structural Maintenance of Chromosomes (SMC) family and regulates gene expression and DNA repair. CONCLUSIONS Patients carrying the deletion of 9q31.1-q32 showed similar phenotypes with CdLS.