Cartilage Hair Hypoplasia

Cartilage Hair Hypoplasia (CHH) is also known as metaphyseal dysplasia, McKusick type. The disorder was recognized as a clinical entity in 1965, when Victor McKusick and colleagues described the condition in an inbred Amish population (1). The term “metaphyseal” relates to the metaphysis, which is the wide region located at the ends of long bones. The name “Cartilage Hair Hypoplasia” was coined due to the characteristic features: fine, sparse hair and cartilage abnormalities.

 
How Cartilage Hair Hypoplasia Is Inherited

Cartilage Hair Hypoplasia is typically inherited in an autosomal recessive manner (2).

 
Causes of Cartilage Hair Hypoplasia

This dysplasia is caused by a mutation of the gene encoding the RNA component of the ribonuclease mitochondrial RNA processing complex (RMRP). The locus of the RMRP gene is on chromosome 9p13. The mutation affects cartilage development.

 
Physical Characteristics

Cartilage Hair Hypoplasia is a relatively rare congenital disorder. It is most prevalent among the Old-world Amish and Finnish populations. Among Amish people, the incidence is approximately 1.5 in 1000 live births, whereas in Finland, it is 1 in 18,000 to 23,000 (2).

The physical characteristics of Cartilage Hair Hypoplasia include a short limbed form of disproportionate short stature with fine, sparse hair. Intelligence is typically average.

Face and Skull:
  • Relatively average face and skull
  • Fine, sparse, and light hair
  • Sparse eyebrows and eyelashes
Trunk, Chest and Spine:
  • Anterolateral chest deformity
  • Prominent sternum
  • Moderately flared lower rib cage
Arms & Legs:
  • Rhizomelic shortening of the limbs
  • Limited elbow extension, but otherwise ligamentous laxity
  • Short and pudgy hands and feet
  • Possible ankle deformity due to the excessive distal length of
    the fibula
  • Mild bowing of the legs
  • Flat feet
  • Prominent heels
What are the X-ray characteristics?

The major radiographic features in infancy include shortened long tubular bones. The femur is curved with rounded distal epiphyses. Anterior angulation of the sternum and short ribs are also characteristic. The radiographic features in children and adults include short, flared, and irregularly sclerotic metaphyses of tubular bones.

Deformities are more prominent in the knee region than in the proximal femur. A postero-lateral subluxation of the radial head is observed in some patients. The fibula is disproportionately long, most notably at the distal end.

There is minimal craniocaudal widening of interpediculate distance in lumbar spine. Small sagittal and coronal diameters of the vertebrae are typical. Flaring and cupping at the costochondral junction of ribs is also characteristic. The metacarpals and phalanges are severely affected.

 
Making the Diagnosis

In infancy, diagnosis of Cartilage Hair Hypoplasia is difficult; not until 9 to 12 months of age do the abnormalities become apparent. Radiographic examination provides the greatest insight. Widened metaphyses, short long bones, elongated fibulae, and anterior angulation of the sternum are all indicative of Cartilage Hair Hypoplasia. Hair hypoplasia is only a positive criterion; the absence of hair hypoplasia does not warrant the exclusion of Cartilage Hair Hypoplasia as a possible diagnosis.

 
Musculoskeletal Problems
Bowing of Legs

Mild bowing of the legs, either genu valgus or genu varum is characteristic and may require corrective osteotomy. Subluxation of the hips may require also surgery. Legg-Perthes disease has been reported in both male and female patients.

Scoliosis

Scoliosis is typical of Cartilage Hair Hypoplasia. Depending on the degree of curvature, it can be managed observation, bracing, or surgery.

 
Problems Elsewhere in the Body
Intestinal Malabsorption

Intestinal malabsorption occurs in approximately 10% of patients. The intestinal malabsorption problem tends to improve on its own.

Hirschsprung Disease

Hirschsprung Disease occurs in approximately 10% of patients. Surgical intervention is oftentimes necessary. Postoperative mortality rates are nearly 40%, due to severe enterocolitis-related septicemia and a compromised immune system.

Humoral Immunity

Humoral immunity is typically compromised. Nearly 56% of younger children experience recurrent infections, especially respiratory tract infections. Children are unusually susceptible to chicken pox. In McKusick’s original study, 6 patients died due to fatal varicella pneumonia. Currently, Acyclovir is most often prescribed to treat the varicella. Patients have a predisposition to cancer, especially non-Hodgkin’s lymphoma and basal cell carcinoma. Again, this susceptibility is due to the compromised T-cell immunity.

Anemia

Anemia can occur in varying degrees in childhood. In anemic patients, decreased red blood cell proliferation is also observed. Most anemic patients recover spontaneously by adulthood; however fatal hypoplastic anemia can occur in infants. The prevalence of anaemia seems to correlate to the severity of the immunodeficiency and the degree of growth failure.

 
What to Look For

It is vital to keep a close watch for the possibility of serious infection or malignancy. Varicella and other live virus vaccinations should not be given if the diagnosis is established.

 
References
  1. McKusick, V. A.; Eldridge, R.; Hostetler, J. A.; Egeland, J. A.; Ruangwit, U. Dwarfism in the Amish. II. Cartilage-hair hypoplasia. Bull. Johns Hopkins Hosp. 116: 285-326, 1965.
  2. Mäkitie, Outi. Cartilage-Hair Hypoplasia: Clinic radiological and genetic study of an inherited skeletal dysplasia. University of Helsinki, Finland. 1992.

Trusted Insights from Nemours' KidsHealth

Relaxation Techniques for Children With Serious Illness

Managing Stress

Nothing about serious illness is easy, but one of the hardest things for parents may be watching their child struggle with pain, stress, and anxiety.

Despite what we may sometimes tell ourselves, stress is not just "in our heads." The stress response — also called the flight-or-fight response — causes a rush of adrenaline and other hormones that trigger physical changes in the body: your heart races, your blood pressure rises, you breathe faster, your digestion slows, and your pupils dilate. Chronic stress takes a toll on the body as well as the mind.

The good news is that using a variety of mind-body relaxation techniques can help short-circuit the flight-or-fight response. Relaxation techniques not only can lessen a child's physical symptoms, they can also help him or her (and you!) regain a sense of control and confidence over a situation, helping everyone find moments of peace amid the chaos and isolation of illness and medical treatment.

Techniques That Can Help

These techniques are designed for parents and kids to practice together. Most can be done in a few minutes wherever you are, whether that's a quiet place or a crowded hospital, without any special tools.

However, it's important to note that these techniques should be used as a complement to conventional medical treatment for anxiety and pain, and not as a replacement — doing so could do a child more harm than good.

If your child is suffering from anxiety or pain, ask your doctor what can be done to help. And always check with your health care team to make sure that your child's symptoms are related to stress and not a different medical problem.

Focused Breathing

Pain and stress can leave a child breathing faster and shallower, or even holding his or her breath — all of which can actually keep the stress response going and heighten the intensity of pain. Paying attention to breathing can help calm the mind.

Try this exercise with your child:

  • Step 1. Sit or lie comfortably and put one hand on your stomach, the other on your chest.
  • Step 2. Close your eyes and try to relax all of your muscles, one by one, from the tips of your toes to the top of your head. Don't forget to relax the muscles in your face, neck, and jaw; you may be storing a lot of tension there.
  • Step 3. Breathe deeply and regularly for several minutes— and try to make your stomach (abdomen) rise and fall, not only your chest. This will help you deepen your breath.
  • Step 4. Pay attention to each breath; try to turn all your thoughts to each inhale … exhale. As you breathe out, imagine the tension leaving your body with the breath.

At first, it may be difficult for you and your child to focus on breathing. Distracting thoughts are normal — but rather than following a thought and letting it consume you, try to let it drift out of your mind, like a balloon.

Relaxation Response Method

This technique asks a person to focus on breathing and quiet the mind to create a sense of calmness and well-being. And by repeating a word, phrase, or prayer during the exercise, the mind is able to stay focused more easily. When practicing this, it's normal for thoughts to pop into the mind. Tell your child to disregard them and just focus on the word or phrase he or she is repeating.

Resembling an Eastern form of meditation, this technique — called the relaxation response — was popularized and put into Western practice in the 1970s by Herbert Benson, MD. To elicit the relaxation response, follow Steps 1-4 above, and then:

  • Step 5. Pick a focus word, phrase, sound, or prayer such as "om," "one," or "peace."
  • Step 6. As you breathe, say the focus word silently to yourself as you exhale.
  • Step 7. Continue for 5 or 10 minutes, ideally building up to 10 to 20 minutes for each session.
  • Step 8. When you're finished, do not stand up immediately. Continue sitting quietly for a bit, letting other thoughts back into your mind. Open your eyes, but stay sitting for another minute before getting up.

When practicing, go at your own pace. Don't feel like you have to achieve a deep level of relaxation right away. Often, feelings of calmness and well-being are felt later on or at times of crisis.

To achieve ongoing results, try to practice the technique with your child once or twice daily, but not within 2 hours after eating, as digestion can interfere with the relaxation response. Some people find that the best time to meditate is first thing in the morning, before breakfast.

Guided Imagery

A growing body of medical research suggests that imagery also can help lessen pain and anxiety, and promote positive feelings. In fact, studies have found that people who practice guided imagery during chemotherapy feel more relaxed and positive about their chemo experience than those who don't use the technique.

Guided imagery (also called "visualization") often works best when a person starts with a few minutes of focused breathing. Here's how it works: With eyes closed, imagine a safe place or a location you once visited that brought a feeling of contentment and joy. Hold on to the image of that place for a while, trying to picture all the sights and sounds:

  • What does the ground beneath you feel like? Is it weather warm or a chilly? Is there a breeze?
  • Are there any animal noises in the distance, or nature sounds (like running water) that you could hear?

Getting as descriptive as possible about this safe place will help you and your child get "into" the moment and feel relaxed.

Some children find this exercise more helpful when they are "guided" by a parent, another live instructor, or with a guided imagery CD or DVD.

As with meditation, distracting thoughts will float into the mind as you practice guided imagery. Acknowledge these thoughts, and then let them drift away while you move your attention back to the images in your mind and sounds you hear.

Music Therapy

Just as pleasant images can calm the mind and soothe the body, so can music. Kids who undergo music therapy — the research-based use of music to lift moods and promote mental and physical well-being — have been found to have lowered heart rates and blood pressure, and improved anxiety.

Many hospitals provide a licensed, trained music therapist who can work individually with kids to develop a customized treatment plan that engages them in:

  • active play that includes listening to music
  • dancing or moving the body to music
  • playing instruments or improvising on them
  • singing along

To participate in music therapy, your child doesn't need to read music or have any special musical talents. And the best part is that you can practice music therapy at home. By choosing music that both you and your child enjoy — and setting aside time to listen, dance, sing, or experiment with an instrument together — you, too, can teach your child the joys of music.

Energy Therapy

Energy therapy is based on the theory of bioelectromagnetics, the belief that the electrical currents in all living organisms produce magnetic energy fields that extend beyond the body. Proponents of this therapy believe that gentle, light touch or above-the-body hand movements can redirect energy to places where it's needed in an effort to bring energy into "balance" or harmony.

While the principles of energy therapy have not been scientifically proven, practitioners say it promotes healing and helps kids feel more relaxed, less anxious, and less bothered by pain.

Many different types of energy therapy are practiced all over the world, including therapeutic touch, healing touch, Reiki and Johrei (from Japan), and Qi gong (from China).

In the United States, some hospitals offer therapeutic or healing touch as a complement to standard treatments for anxiety, pain, or other medical problems.

And some nurses, doctors, or other health care providers are certified in healing touch techniques. They may be able to offer this service to your child, or teach you how to practice healing touch at home.

Massage Therapy

If you like to take a more hands-on approach to soothing and comforting your child, you might prefer massage. The benefits of massage are well known, offering muscle relaxation and increased blood flow and oxygen to body parts to help alleviate stress and ease pain.

But some types of massage are not recommended for certain types of conditions, so check with your doctor first before massaging your child or taking your child to a massage therapist.

The most common forms of massage used in complementary medicine include:

  • Swedish massage. Therapists use their hands to move muscles and joints with long, gliding strokes, tapping movements, friction (made by moving hands quickly) and kneading. Massage oils may be used, so be sure to tell the therapist about any allergies or sensitivities to ingredients that your child may have.
  • Deep-tissue massage. Many of the same techniques are used as in Swedish massage, only therapists apply more pressure to specific areas, concentrating on the deeper layers of muscles and connective tissue.
  • Trigger-point massage. Like deep-tissue massage, this technique massages deeper layers of tissue, focusing on what therapists call trigger points ("knots") within the connective tissue or muscles that are usually painful when pressed.

Many hospitals have massage therapists on hand to offer massages to both patients and their family members, so find out if massage therapy is offered at your hospital.

Learn More

These are just a few of the many methods designed to help patients and families cope with pain and anxiety. Many people find that yoga, stretching, or light, gentle exercise also helps to quiet the mind and sooth the body.

To learn more about relaxation techniques, talk to your child's health care team.

Reviewed by: Larissa Hirsch, MD, and Walle Adams-Gerdts, RN, BA, HTCP/I
Date reviewed: April 2011