How do people inherit Cornelia de Lange syndrome?
When Cornelia de Lange syndrome is caused by mutations in the NIPBL or SMC3 gene, this condition is considered to have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. Almost all cases result from new gene mutations and occur in people with no history of the condition in their family. Cases of Cornelia de Lange syndrome caused by SMC1A gene mutations have an X-linked pattern of inheritance. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. Studies of X-linked Cornelia de Lange syndrome indicate that one copy of the altered gene in each cell may be sufficient to cause the condition. Unlike most X-linked conditions, in which males are more frequently affected or experience more severe symptoms than females, X-linked Cornelia de Lange syndrome appears to affect males and females simila
