Background
Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning.
Methods
The International CdLS Consensus Group comprised 43 participants from 30 institutions in 9 countries. The group consisted of clinicians, scientists and two patient-group representatives. The clinicians practice in North America, South America and Europe. A modified Delphi consensus process was adopted (Table 1). Discussions occurred via video conference calls, e-mail communications and file exchanges. All known support groups were contacted by e-mail to identify key issues that should be addressed during the consensus process. Subsequently, the issues to be addressed were determined by the Consensus Group in a video conference call. A plenary face-to-face 2-day meeting of 17 participants (including the patient-group representatives) was held in November 2017. Consensus recommendations were voted on by 37 participants (for recommendations R1–R68, see Supplementary Box 1).
Conclusion
The present recommendations provide a framework for improving diagnosis and management of CdLS. CdLS is a complex disorder, in which many body systems are affected, and it is important that a lead clinician is identified for each patient to ensure coordination of the numerous aspects of care in both childhood and adulthood. The proposed clinical and molecular diagnostic pathways are intended to be universally practical, both in countries with access to modern techniques and in those where this is not yet possible, and they are meant to be cost-effective, avoiding unnecessary diagnostic or management procedures. Still, in some health-care systems and medicolegal environments, the guidelines may need to be adapted. It is important that implementation of the consensus recommendations is accompanied by prospective audits in order to expand the evidence base and allow for future ameliorations of the consensus.
Reference
Kline, A.D., Moss, J.F., Selicorni, A. et al. Diagnosis and management of Cornelia de Lange syndrome: first international consensus statement. Nat Rev Genet 19, 649–666 (2018). https://doi.org/10.1038/s41576-018-0031-0