Input (grade 13): This condition is about as rare as conjoined twins, affecting one out of every 100,000 live births and is usually fatal within a day or two of birth because of kidney and bladder complications.
Output (grade 8): This, however, is as rare as conjoined twins, and only happens to one out of every 100,000 live births. It is usually very bad for the kidney and bladder, and only about four survivors were known to be alive as of July 2003.