In Texas, Runaway is a status offense that applies to juveniles. Once you turned 17 you became an adult under the criminal justice system, and no longer a juvenile. You cannot be termed a runaway. If the authorities/parents know your location, then you also cannot be termed a missing person. Provided there are no outstanding court orders which restrict or limit your residence, then you can leave home, despite that you are still a minor under civil law, and must remain in school.
The above answer does not create an attorney/client relationship. These responses are merely intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney in your community. The law changes frequently and varies from state to state. You should verify and confirm any information provided with an attorney licensed in your state
Sign up to receive a 3-part series of useful information and advice about child custody law.