Yellow discoloration of the skin and whites of the eyes due to an abnormally high level of bilirubin in the bloodstream, which is then excreted through the kidneys.

Present at birth or appearing as the child grows, can cause chewing and eating problems, abnormal speech and eventually lead to the early loss of the child’s teeth.

Describing joints that easily move beyond the normal range. It is commonly called being ‘double-jointed,’ although these individuals do not have two separate joints.

A rare form of Huntington Disease that begins before the age of 20, occurring in about 10% of Huntington cases, a hereditary, degenerative disease.

Juvenile idiopathic arthritis (juvenile rheumatoid arthritis) is form of arthritis in children 16 or younger. Learn about causes, symptoms & treatment.

A group of diseases causing muscle weakness, joint pain, fatigue, clumsiness, a rash on the face and around joints, irritability, weight loss and ulcers in the mouth.

Depending on which muscles are weak (the stomach, arm, back and thigh muscles), the child may have trouble reaching up, bending down or climbing. A rash may be present.

Juvenile nasopharyngeal angiofibroma (JNA) is an aggressive but rare and benign (non-cancerous) tumor of the nasopharynx, the space behind the nose that connects it to the mouth. Learn more.

A disorder occurring in young people with growth plates not closed yet; a loosening of a piece of bone and the cartilage that covers it; can lead to early arthritis.

In children, the term osteoporosis is used when the density of the bones is significantly below normal (noted on the DXA scan) and they have a fracture history. Learn more.

Also called juvenile idiopathic arthritis, may affect many joints in the body, may cause abnormalities in the growth of joint surfaces, leading to growth issues and pain.