WACO — Baylor center Isaiah Austin, a former standout at Grace Prep in Arlington, has been forced to end his basketball career after being diagnosed with a rare genetic disorder.Austin was found to have Marfan syndrome, a disorder that affects the body’s connective tissue. Baylor coach Scott Drew said Sunday in a news release that the discovery means Austin will not be able to play in the NBA. The 7-foot-1 Austin averaged 12.1 points and 6.9 rebounds this season and announced in April that he would leave Baylor after his sophomore season. The NBA draft is Thursday. According to the Mayo Clinic, complications from Marfan syndrome can weaken the aorta, the artery that supplies blood from the heart to the rest of the body. Drew says he hopes Austin will return to school and finish his degree.