text: Since there are no real characteristics to this syndrome, the doctor will not know that a male has this unless the patient is in need of genetic testing for another reason such as testing the paternaty of a child.  This syndrome is only characterized by physical symptoms all of which can be related to other health problems.  So the long and short of it is a DNA test can determine if you have Jacob's Syndrome.  Hope this answers your question right along with my resource.