The GREM1 gene leads to hereditary mixed polyposis syndrome, characterized by multiple polyps of mixed pathology and high risks for colorectal cancer.
A specific duplication in the 5′ regulatory region of the GREM1 gene has been found in a subset of Ashkenazi Jewish individuals with hereditary mixed polyposis syndrome; therefore, GREM1 genetic testing is often limited to this specific duplication.
However, findings from a study suggest other distinct duplications may cause hereditary mixed polyposis syndrome, regardless of ethnicity.
Consequently, comprehensive GREM1 testing may be considered in individuals who previously had normal genetic test results, regardless of ethnicity, and have a personal and/or family history that remains suspicious for hereditary mixed polyposis syndrome.
Check out the article at https://www.ncbi.nlm.nih.gov/pubmed/29804199