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Hemophilia B is very rare— out of the 20,000 Americans who have hemophilia, only about 4,000 have hemophilia B. If you have hemophilia B (also called Christmas Disease), you are missing or have a deficiency (lower level) of clotting factor IX (FIX). This means that your blood cannot successfully form a clot. Hemophilia B is hereditary. Because it is an X chromosome-linked condition, males are more typically affected and therefore more frequently diagnosed. Hemophilia B affects 1 in 500 male births in the U.S., and approximately 100 babies are born with hemophilia B each year. Approximately 400,000 people worldwide are living with hemophilia, and about 20,000 are living with it in the United States. All races and economic groups are affected equally. Most people with hemophilia B who have access to factor replacement therapy have a normal life expectancy and are able to lead a fairly normal life.

If you have hemophilia B, you should have regular checkups with a hematologist or visit an HTC annually. If you or someone in your family experiences hemophilia B symptoms, and you have not yet been diagnosed, you should contact your medical provider for a referral to a hematologist or HTC for testing and diagnosis.

Fun Facts About Hemophilia B

  • The name Bethesda Units (BUs) was adopted at a conference that occurred in Bethesda, MD.
  • Alternative Names: Christmas Disease; factor IX hemophilia; bleeding disorder – hemophilia B
  • Famous people with hemophilia B:
  • Prince Leopold: Born on April 7, 1853, Prince Leopold was the son of Queen Victoria. He was diagnosed with hemophilia as a child and constantly had doctors around. On April 27,1882, he married Princess Helene Friederike. They had their first child in 1883 and named her Alice. On March 27, 1884 Leopold slipped and fell, injuring his knee and his head. He died early the next morning. His death came 4 months before the birth of his son, Charles Edward.
  • Queen Victoria: Queen Victoria was born on May 24, 1819. Her father died in 1820, and she was raised by her German-born mother. She inherited the throne of England when she was 18 after all three of her father’s older brothers died without any children. She married Prince Albert in 1840, and they had nine children. All 9 of their children and 26 of their 34 grandchildren who survived to adulthood married into royal and noble families across Europe. She reigned for more than 63 years until her death on January 22, 1901. Queen Victoria was a carrier of Hemophilia B. Two of her five daughters were also carriers and married into other royal families in Europe. They passed hemophilia B through various royal families in countries such as Spain, Germany, and Russia. This is why hemophilia B is known as the Royal Disease.
  • Tsarevitch Alexei Nikolaevich: Alexei was born with hemophilia B (which could be traced back to his maternal great grandmother Queen Victoria) on August 12, 1904. He was the youngest child and only son of Emperor Nicholas II and Empress Alexandra Feodorovna. He was the heir to the throne of the Russian Empire. Alexei was killed with his parents and sisters during the Russian Civil War on July 17, 1918. He was in a wheelchair due to complications with his hemophilia B. The family was all put into a room, and a shooting squad was ordered to shoot them, first his father, then him. They shot Alexei several times, but he remained alive. The men then repeatedly stabbed him with bayonets. He was injured but still alive. They then shot him in the head two times, and he finally passed. The men did not know that under his shirt he wore a vest made of gems that protected him from most of these injuries. His body was later burned. He and his family were canonized by the Russian Orthodox Church in 1981 as Holy Martyrs. They were canonized again in 2000 by the Russian Orthodox Church as Passion Bearers. In 2007, a Russian archeologist discovered the remains of two bodies, and based on how they were killed and clothing that was found, announced that they were Alexei and one of his sisters. In 2008, DNA results of the remains confirmed his theory.
  • Chris Bombardier summited Mount Everest on May 22, 2017.

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