What are the genetic changes related to congenital cataracts, facial dysmorphism, and neuropathy ?
A mutation in the CTDP1 gene causes CCFDN. The CTDP1 gene provides instructions for making a protein called carboxy-terminal domain phosphatase 1. This protein helps regulate the process of transcription, which is a key step in using the information carried by genes to direct the production (synthesis) of proteins.  All known individuals with CCFDN have the same mutation in both copies of the CTDP1 gene in each cell. This mutation alters the way the gene's instructions are pieced together to produce the carboxy-terminal domain phosphatase 1 protein. The altered instructions introduce a premature stop signal, resulting in an abnormally short, nonfunctional protein that cannot regulate transcription. Defective regulation of the transcription process affects the development and function of many parts of the body. It is not known how nonfunctional carboxy-terminal domain phosphatase 1 protein results in the specific signs and symptoms of CCFDN.