(Portland, OR)  --  Police are searching for a missing eight-year-old boy and his sister.  The Clackamas County Sheriff's Office says Elijah Leach and his adult sister were last seen Monday afternoon at the Gresham Winco.  Elijah was last seen wearing a red and black jacket with black and grey sweatpants, and police say he suffers from asthma.  Anyone with information is urged to contact police.