Answer:
In most jurisdictions a parent can disinherit a child as long as the will conforms to state law.
You must have a valid reason to contest a will. Reasons include undue influence, error, fraud, technical mistakes in the drafting if the will or questionable legal capacity of the testator. Is there a "no-contest" clause in the will and is it enforceable in your state. You should consult with an attorney who specializes in probate law in your area to determine if you have any valid cause of action before wasting your time and money and the court's time and money.