YOUR SISTER HAS CYSTIC FIBROSIS AND YOU ARE CONTEMPLATING HAVING CHILDREN OF YOUR OWN. YOUR MATE RECALLS HAVING A COUSIN WITH THE DISEASE. WHAT IS THE RISK THAT ONE OR MORE OF YOUR CHILDREN WILL HAVE CYSTIC FIBROSIS? IF YOU CAN DRAW A PEDIGREE OF YOUR FAMILY, ASSUMING YOU HAVE ONLY ONE SISTER AND YOUR MATE HAS ONLY ONE SISTER.