What is cartilage hair hypoplasia?

Cartilage hair hypoplasia is a genetic disorder that affects the metaphyseal area of the long bone — the wider part at the end — causing lower-extremity abnormalities. The condition is an autosomal recessive disorder, meaning it is passed on to a child by both parents. The defect is caused by a problem with the spherical or rod-shaped parts of a cell called mitochondria.

What are the symptoms of cartilage hair hypoplasia?

Individuals with cartilage hair hypoplasia have:

• Light, fine, sparse hair

• Loose ligaments in the elbows, causing instability

• Bowing of their legs (genu varum)

• Possible neck instability

• Risk of infections due to a change in immunity (which is protection from infections)

• Risk of anemia, which lessens with age

• High risk of cancers which can decrease life expectancy

Medical follow-up is important for patients with this type of dysplasia.  

Other Orthopaedic Conditions That Affect Individuals with Cartilage Hair Hypoplasia

• Cervical instability: Caused by the underdevelopment of the second neck vertebra of the spine.

• Scoliosis

• Kyphosis

• Hip dislocation: in about 3 percent of the patients with this disorder

• Lower-extremity misalignment

• Premature arthritis of the hips and knees

Cartilage Hair Hypoplasia Diagnosis

A full physical exam will be done. X-rays of the neck, spine, pelvis (hips) and legs will be ordered to diagnose cartilage hair hypoplasia and/or related conditions, like scoliosis and kyphosis.

Cartilage Hair Hypoplasia Treatment

There are multiple treatment options for the symptoms of cartilage hair hypoplasia based on the area and severity of the condition. They include:

• Cervical fusion with possible placement of halo for cervical instability

• Posterior spinal fusion or placement of growing rods for scoliosis and kyphosis if it progresses

• Traditional treatment for hips if there is dislocation

• Lower-extremity osteotomies (bone realignment) if there is misalignment

• Total joint replacements of the knees and hips if there is severe arthritis