Why do some people are wisdom tooth and some do not have any? are this born with it, primary symptom?

Normal Variation: It has to do with genetic variations, some people have them some don't. If any question go to your dentist for an X-ray.

Wisdom teeth: Wisdom teeth generally appear between the ages of 17 and 25.Most adults have four wisdom teeth but it is possible to have fewer or more (genetically determined), in which case the extras are called supernumerary teeth.Wisdom teeth commonly affect other teeth becoming impacted or coming in "side ways" causing crowding and pain. They are generally extracted if this happens

Genetic drift: Our stone-aged ancestors wore teeth down, so wisdom teeth were necessary replacements. We don't wear our teeth severely, and are faces are getting smaller over time, so Mother Nature started the natural selection process of congenitally missing teeth. Modern Dentistry has allowed us to get around a lot of these problems. See your Dentist for advice.