Geneva Foster, the boy's mother, and Michael Ryan, his stepfather, were arrested and charged with felony injury to a child for keeping the boy locked in a closet or attic without food, MyFoxHouston reported.

The boy also showed signs of brutal physical abuse -- broken bones, bite scars and damage to his liver, pancreas and kidneys, according to the Harris County Sheriff's Office.

A spokeswoman for Child Protective Services told MyFoxHouston that the boy weighed only 72 pounds and had the appearance of a 7-year-old when he was discovered, and that his only nourishment came from cans of diet supplement Ensure.

Four other children who lived in the home were removed and placed in foster care, but the 13-year-old appeared to be the only one of the five children who was abused, MyFoxHouston reported. The boy was taken to a local hospital.

Foster and Ryan are being held on $250,000 bail each.