What does autism have to do with hereditary cancer? In most cases, nothing. But in honor of Autism Awareness Month, we want to highlight the connection between having a mutation (also known as a pathogenic variant) in a gene called PTEN and an increased likelihood of both cancer and autism spectrum disorder.

PTEN mutations cause PTEN Hamartoma Tumor Syndrome (PHTS). This is a spectrum of overlapping genetic conditions: Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS), PTEN-related Proteus syndrome (PS), and Proteus-like syndrome. The specific PHTS condition that a person/family with a PTEN mutation is diagnosed with depends on that person or family’s symptoms/findings. However, these conditions can be variable, even within the same family.

People with Cowden syndrome are at increased risk for cancer, benign tumors, other characteristic benign findings, intellectual disability, and autism. The main associated cancers include breast, uterine, and thyroid cancers. Colon cancer, kidney cancer, and melanoma can also be seen. Characteristic benign findings include macrocephaly (large head size), colon polyps, distinctive skin lesions, and thyroid growths.

What is the take-home message here? A detailed personal and family history should include not only the cancers in a family, but also the presence of non-cancerous physical and developmental findings such as macrocephaly and autism spectrum disorder. Meeting with a genetic counselor to fully scope out personal and family histories increases the likelihood that the right genetic test is ordered.