The United Cerebral Palsy Association of Metropolitan Boston is sponsoring a jog-a-thon Sunday, April 28, at 11 a.m. beginning at the Marriot Motor Hotel on Route 128. The object of the event is to obtain sponsors for each runner to pay a dollar or more per mile. The proceeds will go to the United Cerebral Palsy Association. Registration forms may be obtained by writing to Johnny Kelley, UCP of Metropolitan Boston, 210 Webster Street, West Newton, Ma. 02165, or by calling 965-9850. Registration entries must be received before April 25. The jog-a-thon entries may run up to 5 miles at their own speed. It will not be a competitive race but rather a "fun" get together for runners or joggers in support of UCP.