Is that true that if the childs asthma is gone before 7 yrs old, it will never come back anymore?

Not necesarily: If a definite diagnosis of asthma has been made, as the child matures symptoms may become less frequent and appear to disappear. However, it may reappear later in life. The severity of the asthma and issues like allergies that progress into adulthood mau be factors as well.

No, not true: Sorry but that is not true. Some children indeed as they get older may experience fewer symptoms of and exacerbations of asthma. Yes it is possible that a child with asthma may grow up and not have anymore asthma problems as an adult. This should never be assumed and the patient with a diagnosis of asthma should carry a rescue inhaler at all times. Likely a good topic for discussion with your doc.