The central feature of the disease is the presence of blood in the urine (hematuria). Boys with X-linked Alport Syndrome develop hematuria in infancy, and it is always present. The great majority of girls with X-linked Alport Syndrome also have hematuria; the hematuria of Alport Syndrome is usually microscopic, meaning it can only be detected with a microscope or a urine dipstick. Sometimes children with Alport Syndrome have brown, pink or red urine (gross hematuria) for several days, brought on by a cold or the flu. This gross hematuria will go away on its own and while it may be frightening, it is not harmful.