Cornelia de Lange syndrome is a developmental disorder that affects many parts of the body. The severity of the condition and the associated signs and symptoms can vary widely, but may include distinctive facial characteristics, growth delays, intellectual disability and limb defects.
Patients experience a range of physical, cognitive, and medical challenges ranging from mild to severe.
Approximately 60% of people affected by CdLS have a disease-causing variation (mutation) in the Nipped-B-like protein gene, and about 10% of cases are caused by mutations in one of four known genes: SMC1A, SMC3, HDAC8 and RAD21. In the remaining 30% of cases, the underlying genetic cause of the condition is unknown. CdLS can be inherited in an autosomal dominant (NIPBL, SMC2, or RAD21) or X-linked (SMC1A or HDAC8) manner.