Molecular characteristics

The condition is caused by a DNA change in one copy of the gene DDB1. So far, this DNA change has always been a new change in the individual affected with the condition. Most of the changes have been missense variants, meaning the DNA code has a substitution in it to another nucleotide, resulting in a substitution of a different amino acid into the DDB1 protein. Studies have shown that cells from people with the condition show an impairment of DNA repair. The mechanism by which these DNA changes cause the condition is not yet known.