Factor X Deficiency

Factor X deficiency is a rare bleeding disorder that varies in severity among affected individuals. The signs and symptoms of this condition can begin at any age, although the most severe cases are apparent in childhood. Factor X deficiency commonly causes nosebleeds, easy bruising, bleeding under the skin, bleeding of the gums, blood in the urine (hematuria), and prolonged or excessive bleeding following surgery or trauma. Women with factor X deficiency can have heavy or prolonged menstrual bleeding (menorrhagia) or excessive bleeding in childbirth, and may be at increased risk of pregnancy loss (miscarriage). Bleeding into joint spaces (hemarthrosis) occasionally occurs. Severely affected individuals have an increased risk of bleeding inside the skull (intracranial hemorrhage), in the lungs (pulmonary hemorrhage), or in the gastrointestinal tract, which can be life-threatening.


Factor X Deficiency
WHAT YOU SHOULD KNOW Whether you are newly diagnosed with Factor X Deficiency (FX Deficiency) or have been diagnosed for some time, it is common to go through many ups and downs. We want to share information that you should know and some resources about this condition that can help you on your path to improved health and quality of life. When you are first given a new diagnosis, one as rare as FX Deficiency, it is understandable to have many emotions or feel overwhelmed. The good thing is that you're The National Hemophilia Foundation (NHF) is here to provide you with education and support as you manage your bleeding disorder whether you are a child, a teen, or an adult. In this spirit, NHF and the bleeding disorders community have selected some of the most frequently asked questions and answers below to empower you. not alone. There are other people who have the same condition and lead full lives. They have had their lives enriched by becoming closer to other people who are traveling on a similar path. With the care of an experienced team, you will find support from your healthcare providers as well as from the vibrant and caring bleeding disorders community. You can be involved in this community and build meaningful relationships with your new extended family.
"There are other people who have the same condition and lead full lives. They have had their lives enriched by becoming closer to other people who are traveling on a similar path." You are NOT alone.
FX Deficiency is an ultra-rare bleeding disorder. Bleeding disorders are a group of medical conditions marked by an inability or decreased ability to form a stable blood clot. When the body is injured and an area bleeds, a clot is formed to stop the bleeding. Clot formation is a multistep process called coagulation. When the blood clots properly, the blood clot is held together firmly at the site of the injury. People with a bleeding disorder are unable to make strong clots or none at all. Improper clotting can be caused by abnormalities in blood components such as platelets and/or blood clotting proteins, also called clotting factors. Platelets are small blood cells that help blood clot. Platelets act like first responders and stop bleeding by clumping and forming plugs in blood vessel injuries. This initial plug is strengthened by the formation of a mesh-like network termed fibrin that is generated by a series of clotting proteins.
If any clotting protein is defective, deficient, or absent, the clot formation will be inadequate, and bleeding will happen. FX is one of the clotting factors that is an important part of this process and works by making the clot strong or stable. FX Deficiency is caused by an abnormal function or decreased amount of the protein. FX Deficiency affects approximately 1 in 500,000-1,000,000. 1 It is also known as Stuart-Prower Factor Deficiency, named after the first two patients diagnosed with this condition. 1

What Is Factor X Deficiency?
"Bleeding disorders are a group of medical conditions that share an inability or decreased ability to form a stable blood clot." FX Deficiency is an inherited bleeding disorder, meaning that it is passed on from biological parents to child at the time of conception.
• It affects both males and females equally.
• The affected person has two abnormal copies of a defective gene. • • A carrier has only one copy of a defective gene. Typically, carriers do not have bleeding symptoms.
• For someone to inherit FX Deficiency they must inherit a copy of the defective gene from both biological parents. That means both parents must be affected or are carriers of FX Deficiency.
• This pattern of inheritance is called Autosomal Recessive. It is different from what is called X-linked inheritance, as in the case of some other bleeding disorders like hemophilia. The different forms of autosomal recessive inheritance are illustrated on the next page. Sometimes a person might develop FX Deficiency, rather than being born with it, as noted in patients with other medical conditions including some types of cancer. 2 Such an "acquired deficiency" is still quite rare. It can be caused by an antibody, which is a protein produced by the body's immune system. The antibody interferes with the way FX Deficiency works in the body. Acquired FX Deficiency can also be caused by an unrelated condition called amyloidosis, in which an abnormal protein aggregate (amyloid) binds FX and reduces its level in circulation. If you have acquired FX Deficiency, you may have variable bleeding symptoms that can range from mild to severe.

Family Inheritance of an Autosomal Recessive Disorder
If you are AFFECTED with Factor X Deficiency, you probably inherited one defective gene from each of your biological parents.
If you are a CARRIER of Factor X Deficiency, you inherited only one copy of a defective gene from a biological parent.

How is Factor X Deficiency diagnosed?
The diagnosis of FX Deficiency is challenging because it is rare and the common lab tests to look for this bleeding disorder may show results that are normal.

Persons with the severe form of FX Deficiency are often diagnosed with:
excessive bleeding during infancy, like bleeding following circumcision in boys bleeding when the umbilical cord falls off, around 7-14 days after birth bleeding into the brain (intracranial bleeding) bleeding into the stomach or intestines (gastrointestinal hemorrhage) 4 FX levels are normally low in all infants, even those without FX Deficiency and therefore the measurement may need to be repeated before a diagnosis of FX Deficiency is made. Persons with a mild or moderate deficiency may be diagnosed after some type of challenge, such as a surgery or trauma. The milder forms of the disorder may be diagnosed during routine screening or based on family history. 2 When a bleeding disorder is suspected, your healthcare provider will draw your blood and send your blood to be tested in a lab. The tests will measure how long it takes your blood to clot. If the results of these screening tests are suspicious then a FX Deficiency can be confirmed with a Factor X assay, to measure the level of FX in the blood. The FX assay is a sensitive test that is best done through a Hemophilia Treatment Center (HTC), a comprehensive clinic that specializes in the care of individuals with coagulation disorders. There are two types of FX Deficiency. Your physician can tell you what type you have. 4

How is Factor X Deficiency treated?
For optimal care, it is recommended that you find a specialized doctor, or hematologist, who is experienced in the treatment of FX Deficiency. These doctors often work at a Hemophilia Treatment Center (HTC).
There is one FDA-approved FX concentrate that comes from human blood. In addition to the FX concentrate, fresh frozen plasma (FFP), a part of blood, and other types of factors have been used to treat bleeding in FX deficient patients. 1 FX concentrate may not be readily available, and another concentrate with FX (Profilnine) could be given.
For minor symptoms, topical therapies (applied to the skin) and/or antifibrinolytics (such as tranexamic acid pills that help the clot you make last longer) may be enough to control bleeding without needing to use replacement factor. These can also be used with the FX concentrate. 1 Patients with frequent bleeding, like repeated joint bleeds or severe nose bleeds, may benefit from "prophylactic" treatment 1-2 times per week. Heavy menstrual bleeding may often respond to standard hormonal therapy used for heavy periods in general. Your healthcare provider (HCP) will work with you to develop an ideal treatment plan based on your bleeding history.
For the most current list of FDA-approved treatments for all bleeding disorders, including FX Deficiency, visit: www.hemophilia.org/healthcare-professionals/guidelines-on-care/productslicensed-in-the-us. "There is one FDA-approved FX concentrate that comes from human blood." What special precautions need to be taken when considering pregnancy?
Women with FX Deficiency can experience successful pregnancy, but most will have some degree of bleeding. Women with a severe FX Deficiency can experience several pregnancy-related complications and may require preventive treatment with Factor X concentrate (prophylaxis) during their pregnancy. 5 Meeting with your hematologist is essential prior to getting pregnant. It is important to work closely with a hematologist who is experienced in the treatment of FX Deficiency. Often these specialized doctors are found at a HTC. They can guide your women's health doctor (OB/GYN) to help develop a treatment plan during your pregnancy, labor and delivery, and up to 4-6 weeks after delivery (the postpartum period). HTC hematologists will also be able to provide care to your baby and provide testing as needed.
"Meeting with your hematologist is essential prior to getting pregnant." While we set out with the best intentions for our children, sometimes we encounter pitfalls we never could have envisioned. But often the most challenging journeys become opportunities for finding our best selves. If we seek out knowledge and steer with confidence and optimism, we can enjoy this extraordinary journey alongside those other rare gems sharing the same path."

Parent of a child with FX Deficiency
" Don't let your diagnosis define you, let it inspire you. Be a champion for yourself and others within the bleeding community."

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Having NHF in your corner turns a FX diagnosis from the end of the world into, oddly enough, a unique life opportunity. It is di cult, but you are not alone; there's a whole community waiting to meet you with open arms that you would never have known otherwise."

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Even though you are one in a million you are not alone. The Factor X community is here for you. It's great to be a 10. It's an exclusive club."

FX Patient
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ADVICE FROM OTHER FX COMMUNITY MEMBERS
Where else can I obtain additional information?
You are now part of a family known as the bleeding disorders community. You are not alone and you can turn to other members of this community for support if needed: • Know how to navigate disclosing your or your child's bleeding disorder to daycare, school, work, emergency rooms, and non-hematology specialists.
Learn more about advocating for appropriate treatment in an emergency room (ER) or with other healthcare providers who may not know much about FX Deficiency. Always carry your treatment plan letter provided by your Hemophilia Treatment Center when travelling or going to the emergency room.
Find out where to connect with others with bleeding disorders locally.