Canavan disease is another progressive disorder in which the brain and nervous system degenerate. There is no treatment, and death usually occurs in early childhood. Sometimes there are also abnormalities of the heart, kidneys or limbs. There is a high rate of cancer, especially leukemia, among these patients. There is no treatment, and death occurs by age 4 years.
Bloom syndrome includes poor growth, immune system deficiency and a high rate of cancer.
Affected individuals usually die of cancer before the age of 30 years. Intelligence is normal. Different genes cause each of these diseases, but the way they are inherited is the same. The chances are the same for each pregnancy, no matter how many children the couple has, and are also the same for boys and girls. Carriers are not themselves affected by the disease.