At this time, there is no simple way to prevent hemophilia in someone who inherits a defective gene and thus produces too little clotting factor. If hemophilia runs in your family, you can be tested to see whether you carry the defective gene and receive counseling about your chance for having children with hemophilia.
Gene therapy clinical trials began in early 1999 in an attempt to cure hemophilia, and in vitro fertilization may allow selection and implantation of embryos that lack the hemophilia...
PNH affects everyone differently. Some people have only minor problems, but for others, it's much more severe. The biggest concern is blood clots, which can be deadly. About 40% of people with PNH have one at some point.
PNH comes from your genes, but you don't get it from your parents, and you can't pass it on to your kids.
A change in a gene, called a mutation, causes your body to make abnormal red blood cells. These cells lack proteins that shield them from your immune system. So your body's immune system breaks them down, a process doctors call hemolysis.
Some doctors believe PNH is related to weak bone marrow. People with a certain type of anemia, called aplastic anemia, are more likely to get PNH. The reverse is also true: People with PNH are more likely to get aplastic anemia, though not everyone does. In this condition, your bone marrow stops making new blood cells.
PNH gets its name from one of its more common symptoms. About half of people with PNH pass dark or bright red blood in their urine at night or in the morning. "Paroxysmal" means "sudden," "nocturnal" means "at night," and "hemoglobinuria" means "blood in the urine."