| Syndrome with characteristics of co-occurrence of both juvenile polyposis syndrome and hereditary hemorrhagic telangiectasia. Juvenile polyposis syndrome has characteristics of hamartomatous polyps occurring throughout the gastrointestinal tract. Hereditary hemorrhagic telangiectasia is characterized by vascular dysplasia with telangiectases of the skin, oral and nasal mucosa and arteriovenous malformation of the lungs, liver, brain and gastrointestinal tract. The syndrome is caused by heterozygous mutation in the SMAD4 gene on chromosome 18q21. |
