Down Syndrome markers

We had our 20 week anatomy scan yesterday! Ultrasound tech said baby boy looked great. Today, our OB came in and said she looked over our scans from yesterday, and she said that there was a spot on his heart (she said a big, long name for it) appeared more white than grey on the screen, which she said used to be a marker for DS. She said that usually it will go away by 28 weeks, and she hasn’t seen one yet that has had any health issues.

Have any other moms dealt with anything like this?