- Haemophilia is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding, known as Bleeder's disease.
- It is also a disease that has been prevalent in European royal families. Hence, it is known as the Royal disease.
- Hemophilia A and haemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes.
So, the correct answer is 'Y-linked disease'.