Christmas disease — also called hemophilia B or factor IX hemophilia — is a rare genetic disorder in which your blood does not clot properly. If you have Christmas disease, your body produces little or no blood-clotting factor IX, which leads to prolonged or spontaneous bleeding. The less factor IX your body produces, the worse your symptoms are. Without treatment, Christmas disease can be fatal.
A person is born with Christmas disease, although it may not be diagnosed until later in life. In about two-thirds of cases, Christmas disease is inherited. The other one-third of cases is caused by spontaneous gene mutations that occur for unknown reasons during fetal development. The disease is almost always exclusive to males.
The disease has nothing to do with the Christmas holiday; it was named for Stephen Christmas, who was the first person diagnosed with the condition in 1952. Christmas disease is the second most common form of hemophilia. Approximately one in 3,300 people in the United States have Christmas disease, according to the National Hemophilia Foundation. (NHF)
How Is Christmas Disease Inherited?
The gene responsible for Christmas disease is carried on the X chromosome. Females have two X chromosomes and males have one X and one Y chromosome. If a male inherits the faulty gene on his X chromosome, he could develop Christmas disease. If a female inherits the faulty gene on one of her X chromosomes, she will be a carrier for Christmas disease and may pass the defective gene on to her children.
All daughters of a father who has the defective gene will be Christmas disease carriers. A father does not pass the faulty gene on to his sons. A mother who carries the faulty gene has a 50 percent chance of having a son with Christmas disease and a 50 percent chance of having a daughter who is a carrier of the disease.
Females are usually only carriers because they have two X chromosomes. If they inherit the faulty gene on one X chromosome, the other X chromosome produces sufficient factor IX for blood clotting. However, female carriers may produce less factor IX than women who are not carriers, which can result in mild abnormal bleeding after injuries or surgical procedures. A female can inherit Christmas disease if both of her parents pass the faulty gene on to her — although it is rare for a female to have two parents with the faulty gene.
Genetic Testing for Christmas Disease
If you are a woman with a family history of Christmas disease, you can undergo genetic testing to see if you carry the faulty gene. Genetic testing is more than 99 percent accurate for detecting the faulty gene, according to Barbara A. Konkle and her fellow researchers, as reported in GeneReviews. (GeneReviews)
What Are the Symptoms of Christmas Disease?
Severe cases of Christmas disease are usually diagnosed before the patient is 1 year old. Mild cases may not be diagnosed until a child reaches his or her toddler years (or sometimes even later). In all cases, diagnosis usually happens after abnormal bleeding from an injury or surgery.
Events that may lead your doctor to suspect Christmas disease include:
- prolonged bleeding during circumcision
- prolonged bleeding after surgical procedures or tooth extractions
- prolonged bleeding from cuts or other wounds
- unexplained, excessive bruising
- unexplained, excessive and prolonged nosebleeds
- unexplained blood in the urine or feces caused by internal bleeding in the gastrointestinal or urinary tract
- internal bleeding that pools in the joints, causing pain and swelling
The following symptoms are usually only present in severe cases of Christmas disease:
- unexplained bleeding in the skull after childbirth
- spontaneous bleeding for no apparent reason
Diagnosing Christmas Disease
If you or your child shows symptoms of Christmas disease, a doctor may order blood tests to confirm the diagnosis, including:
- factor IX test to determine how much of the clotting factor is present in your blood
- activated partial thromboplastin time (APTT) test to detect how fast your blood clots
- prothrombin time test, another test to detect how quickly your blood clots
- fibrinogen test to gauge your body’s ability to create a clot
How Is Christmas Disease Treated?
There is no cure for Christmas disease. There are, however, treatments for the condition. Regular treatment is essential for managing the symptoms of Christmas disease.
Factor IX Injections
Christmas disease can be treated with factor IX injections to prevent or stop bleeding. The factor IX can be derived from donated human blood or made in a laboratory. Artificial factor IX is called recombinant factor IX and is generally recommended over blood-derived factor because it is safer. Blood-derived factor IX may contain dangerous pathogens, such as hepatitis or HIV. However, the risks of contracting HIV and hepatitis from factor IX treatment is lower than ever due to improved blood-screening practices.
If you have a mild form of Christmas disease, your doctor may give you a product called desmopressin acetate (DDAVP) to apply to small wounds to stop the bleeding. Larger wounds and internal bleeding require medical treatment from your doctor.
If you have a severe form of Christmas disease, you may need preventive blood transfusions to avoid or reduce prolonged and heavy bleeding.If you receive blood-derived factor or blood transfusions, you should be vaccinated for hepatitis B.
Outlook and Complications
With treatment, you will most likely lead a normal life. There is a slight chance that you could die from excessive blood loss, experience bleeding in the brain or have long-term joint problems from internal bleeding. In rare cases, the treatment for Christmas disease may result in abnormal thrombosis or clot formation.