... or skin A larger than normal head size (macrocephaly) Developmental delays , learning disabilities , and/or autism Dark freckles on the penis Thyroid , kidney , or colorectal cancer Uterine or breast cancer (in females only) If you're pregnant and have a family history of PTEN gene changes , you may consider having the test as part of your prenatal testing . The test can show whether your baby could be born with PTEN hamartoma tumor syndrome. What happens during a PTEN genetic test? If ...