What causes Cornelia de Lange syndrome ?
What causes Cornelia de Lange syndrome? Most cases (approximately 65%) of Cornelia de Lange syndrome (CdLS) are caused by changes (mutations) in the NIPBL gene. An additional 5% of people affected by the condition have mutations in one of four known genes (SMC1A, SMC3, HDAC8 and RAD21). Many of the genes associated with CdLS encode proteins that play an important role in human development before birth. Mutations in these genes may result in an abnormal protein that is not able to carry out its normal function. This is thought to interfere with early development leading to the many signs and symptoms of CdLS. In 30% of people with CdLS, the underlying genetic cause of the condition is unknown.