The word “Metatropic” is derived from the Greek word “Metatropos”, meaning "changing form." Clinically, this dysplasia is one that progresses over time. Metatropic dysplasia is a rare disorder. Because it is so uncommon, the exact incidence is not known.
Metatropic dysplasia has an autosomal dominant inheritance.
This means that those with metatropic dysplasia have a 50/50 chance of passing this condition on to their children, either males or females. Metatropic dysplasia can also happen for the first time in a child; in cases when both parents are of typical stature, the chance to have another child with metatropic dysplasia is low (2-3%).
A change in a gene called TRPV4.
Initially, individuals have shortened limbs with a relatively average-sized trunk (short-limbed dwarfism). As the child gets older and the condition progresses, kyphoscoliosis of the spine develops that decreases trunk height (short-trunk dwarfism). Apparent shortening of the limbs also occurs over time, due to progressive joint contractures.
Trunk, Chest & Spine:
- Small and narrow chest
- Pectus carinatum (chest bone sticking out more than average) or pectus excavatum (depressed breast bone)
- Severe kyphoscoliosis
- In infancy, “coccygeal tail” can be apparent, which is a prolongation of the normal tailbone consisting of cartilage material
Arms & Legs:
- Significantly shortened limbs with a characteristic dumbbell shape bone
- Enlarged joints
- Progressive joint contractures during childhood
What Are the X-ray Characteristics?
The radiographic features of Metatropic Dysplasia include small, flat, diamond-shaped vertebral bodies in early infancy due to defective ossification.
Later, platyspondyly and anterior wedging of vertebral bodies are characteristic. Appearance of a hump-like build-up of bone in both the central and posterior portions of vertebral end plates in the lower posterior and upper lumbar spine. The thorax is narrow and ribs are short in both infancy and early childhood. Limbs are also short with marked metaphyseal flare and epiphyseal dysplasia. Deformed capital femoral epiphyses. Hyperplasia of proximal femoral metaphyses. The capital femoral epiphyses are typically deformed. Hyperplasia of proximal femoral metaphyses is usually observed.
Finally, hypoplasia of basilar pelvis with crescent-shaped iliac crests and low-set anteriosuperior iliac spines is characteristic.
Metatropic dysplasia is diagnosed by its characteristic clinical features such as the coccygeal tail, normal facies, spinal issues, and limb shape. Radiographic features help with diagnosis and genetic testing can also help confirm a diagnosis.
Being a rare disorder with few reports in the medical literature, consultation with an experienced clinical geneticist may be required before a diagnosis is made.
Metatrophic Dysplasia varies in severity. Some infants die from severe respiratory problems whereas others survive with only minor changes.
Atlantoaxial instability is almost universally present in metatropic dysplasia. X-rays of the neck should be performed at diagnosis and at periodical intervals thereafter. Progressive instability in this region will lead to spinal cord compression and is potentially life threatening. Signs of cord compression have been listed elsewhere.
If instability is progressive or symptomatic, early surgical fusion of the affected bones is essential. In cases of diagnostic doubt, further information can be obtained by means of an MRI scan (with flexion-extension views and CSF flow studies). It allows accurate determination of the degree of spinal cord compression and space available for the cord.
Spinal fusion may be supplemented by instrumentation (metal implants) to support the bones until the fusion mass consolidates. Usually extra bone is taken from a rib or from the pelvis to help the healing process. Immobilization of the neck is achieved by a halo vest or body cast, for at least 3 months.
Kyphoscoliosis is commonly seen in early childhood. It is often severe and rapidly progressive. Spinal curves should be diagnosed early and followed-up at regular intervals. Bracing may be of some benefit in younger children with smaller curves (400 to 500).
The timing of spinal decompression and fusion for scoliosis in metatropic dysplasia is dependent upon the severity of the curve, curve progression, age and risk of injury to the spinal cord. Instrumentation of the spinal fusion may not be possible due to the size and structure of the vertebral column. Prolonged immobilization in a halo body cast may be necessary
The status of the respiratory system may dictate the timing of surgery, especially in the younger, more severely affected children. In the lower back, spinal stenosis may occur requiring decompression and spinal fusion.
The limbs are short with significant joint contractures. The treatment of bony deformities and joint contractures is dictated by walking ability, amount of functional compromise and symptoms. Common problems include hip and knee flexion contractures and genu valgus. Some individuals may have signs of ligamentous laxity. Premature degenerative arthritis invariably occurs, requiring joint replacement surgery.
Respiratory problems are the result of a poorly developed, stiff rib cage. Prolonged breathing difficulties may warrant a tracheostomy and long-term ventilatory support. This is a frequent cause of death in infancy.
Other serious but preventable causes of breathing impairment are spinal cord compression and hydrocephalus. Lung function tests and sleep studies are frequently used to diagnose breathing problems in skeletal dysplasias. Regular review by a pulmonologist is recommended.
Hydrocephalus has been reported in metatropic dysplasia. Regular measurement of head circumference will facilitate early diagnosis. Headache, vomiting, visual disturbances, and loss of consciousness are signs of increased pressure around the brain.
In metatropic patients, any change in walking ability, endurance or
breathing should merit further assessment by a physician to rule out
spinal cord compression. Specific neurological symptoms such as
tingling or numbness in the arms or legs, weakness, shooting leg or
arm pain, or problems controlling bladder/bowel function should be investigated further.
One should also watch out for progressive curvature of the spine.
Headache, vomiting, visual disturbances, and loss of consciousness
are signs of increased pressure around the brain; possibly due to
- Jones, Kenneth L. Recognizable Patterns of Human Malformation. Philadelphia, PA: Elsevier Saunders. 2006.
- Krakow D, Vriens J, Camacho N, Luong P, Deixler H, Funari TL, Bacino CA, Irons MB, Holm IA, Sadler L, Okenfuss EB, Janssens A, Voets T, Rimoin DL, Lachman RS, Nilius B, Cohn DH. Mutations in the gene encoding the calcium-permeable ion channel TRPV4 produce spondylometaphyseal dysplasia, Kozlowski type and metatropic dysplasia. Am J Hum Genet. 2009 Mar;84(3):307-15.
- Scott, Charles I. Dwarfism. Clinical Symposium, 1988; 40(1):17-18
- Spranger, Jurgen W. Brill, Paula W. Poznanski, Andrew. Bone Dysplasias: An Atlas of Genetic Disorder of Skeletal Development. Oxford: Oxford University Press. 2002.
From Nemours' KidsHealth
Trusted External Resources
Relaxation Techniques for Children With Serious Illness
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.
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, 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.
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.
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 is based on the understanding that there are electrical currents in all living organisms. This produces magnetic energy fields that extend around and beyond the body, just like the Earth's electromagnetic field. 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 the body into "balance" or harmony.
Energy therapy continues to be scientifically explored and, and findings note that it promotes healing as it helps kids feel more relaxed, less anxious, and less bothered by pain. It also empowers them to feel like they are in control and can do something to help themselves feel better.
Many different types of energy therapy are practiced all over the world, including Healing Touch, therapeutic touch, Reiki and Johrei (from Japan), and Qi gong (from China).
In the United States, many hospitals offer Healing Touch as a complement to standard treatments for anxiety, pain, or other medical problems, meaning that they are used with the therapies and/or medications that the medical teams order.
And some nurses, doctors, or other health care providers are certified in Healing Touch techniques through a required national certification examination. Healing Touch is the only energy therapy with this requirement. They may be able to offer this service to your child, and can teach you how to practice Healing Touch at home.
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.
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 soothe the body.
To learn more about relaxation techniques, talk to your child's health care team.
Reviewed by: Walle Adams-Gerdts, BA, RN, HTCP/I
Date reviewed: September 26, 2016