The Williams Syndrome Association’s medical advisors recommend that those eligible (age 5+) should actively pursue getting the COVID vaccine. There is no reason that we know of that a diagnosis of WS should prohibit a person from getting the vaccine. There may be other issues specific to the individual (previous anaphylaxis to one of the vaccine components or immunocompromised status), that would be rare and not related to WS, but may impact the decision. For those items, they should talk to the doctor that knows them best.
For more information on medical conditions deemed priorities, please view the article linked below.