(EDWARDSVILLE, IL) — Police are searching for a missing Edwardsville teen and her baby son. Authorities say Katherine Derleth, 13, and her infant son Christopher was last seen early Sunday morning. The two are believed to be with Christopher M. Derleth, 39, Katherine’s stepfather. Police say they may be en-route to West Virginia in a green 1997 Mercury Villager Minivan with Illinois license plate number E83-3210. Katherine Derleth is described as a white female, 4’8”, weighing 95 pounds, with brown hair and eyes, and three birthmarks on her right knee. Her son is described as a white male, 21 inches long, weighing 8 pounds and 3 ounces, with brown hair and eyes. Authorities describe Christopher M. Derleth as white male, 6’1”, weighing 160 pounds with brown hair and hazel eyes. If you have any information on their whereabouts, call police.