You'd be forgiven for thinking the so-called 'Christmas Disease' derived its name from the Christian festival itself.
But this alternative name for Haemophilia B really came about because the first patient was called Stephen Christmas. When the five-year-old Canadian was first diagnosed in 1952, there was only one known type of haemophilia – one where people lack the specialised protein clotting factor VIII and are therefore at risk of serious bleeding.
Then Rosemary Biggs and Robert McFarlane, two coagulation researchers, discovered that Christmas lacked not this blood clotting protein but a different one, clotting factor IX, and decided to name the new disease after him.
Both types of haemophilia are lifelong, inherited bleeding disorders and can be classed as mild, moderate or severe.
.Haemophilia is caused by an inherited X-linked recessive trait, meaning the defective gene is located on the X chromosome. This placement is significant: males are more likely to suffer from haemophilia than females because they typically only have one X chromosome, meaning if the IX gene is missing, there is no second copy (as with most females) of X to take over the work of making factor IX.
Teachers, civil servants and train drivers walk out in biggest strike in decadePatients with haemophilia bleed longer but not faster than unaffected individuals. The Centers for Disease Control (CDC) warns that bleeding in a vital organ like the brain can cause long-term problems, such as seizures and paralysis, and on rare occasions even death.
But with the right treatment and care, there's no reason why Haemophilia B patients cannot lead healthy, fulfilled lives – though most are advised to avoid activities such as contact sports.
Blood tests can diagnose haemophilia and ascertain how severe it is. According to the NHS, most cases of Haemophilia B are severe and require preventative treatment, usually, regular injections of a medicine called nonacog alfa (BeneFix), an engineered version of the clotting factor IX which patients are lacking.
Genetic and genomic testing can identify the risk of passing the condition on to a child. There are also tests during pregnancy that can diagnose haemophilia in the foetus, such as chorionic villus sampling (CVS) – wherein a sample of the placenta is tested for the haemophilia gene, usually between 11 and 14 weeks of pregnancy – but these procedures carry a small risk of miscarriage or premature labour.