why is it called christmas disease

The Christmas disease, or X-linked recessive chondrodystrophy (XRD), is a rare genetic disorder that can cause skeletal and other physical abnormalities. The name comes from the fact that it is often diagnosed around the holiday season, when children may have more access to medical care. The disease affects males, and is passed down through the mother's X chromosome. It can cause short stature, spine and joint deformities, hearing loss, and other health issues. It can also affect the immune system, making the individual more prone to infections.