DWARFISM

Signs and symptoms — other than short stature — vary considerably across the spectrum of disorders.

Disproportionate dwarfism

Most people with dwarfism have disorders that cause disproportionately short stature. Usually, this means that a person has an average-size trunk and very short limbs, but some people may have a very short trunk and shortened (but disproportionately large) limbs. In these disorders, the head is disproportionately large compared with the body.

Almost all people with disproportionate dwarfism have normal intellectual capacities. Rare exceptions are usually the result of a secondary factor, such as excess fluid around the brain (hydrocephalus).

The most common cause of dwarfism is a disorder called achondroplasia, which causes disproportionately short stature. This disorder usually results in the following:

• An average-size trunk
• Short arms and legs, with particularly short upper arms and upper legs
• Short fingers, often with a wide separation between the middle and ring fingers
• Limited mobility at the elbows
• A disproportionately large head, with a prominent forehead and a flattened bridge of the nose
• Progressive development of bowed legs
• Progressive development of swayed lower back
• An adult height around 4 feet (122 cm)

Another cause of disproportionate dwarfism is a rare disorder called spondyloepiphyseal dysplasia congenita (SEDC). Signs may include:

• A very short trunk
• A short neck
• Shortened arms and legs
• Average-size hands and feet
• Broad, rounded chest
• Slightly flattened cheekbones
• Opening in the roof of the mouth (cleft palate)
• Hip deformities that result in thighbones turning inward
• A foot that’s twisted or out of shape
• Instability of the neck bones
• Progressive hunching curvature of the upper spine
• Progressive development of swayed lower back
• Vision and hearing problems
• Arthritis and problems with joint movement
• Adult height ranging from 3 feet (91 cm) to just over 4 feet (122 cm)

Proportionate dwarfism

Proportionate dwarfism results from medical conditions present at birth or appearing in early childhood that limit overall growth and development. So the head, trunk and limbs are all small, but they’re proportionate to each other. Because these disorders affect overall growth, many of them result in poor development of one or more body systems.

Growth hormone deficiency is a relatively common cause of proportionate dwarfism. It occurs when the pituitary gland fails to produce an adequate supply of growth hormone, which is essential for normal childhood growth. Signs include:

• Height below the third percentile on standard pediatric growth charts
• Growth rate slower than expected for age
• Delayed or no sexual development during the teen years

DIAGNOSIS

Your pediatrician will likely examine a number of factors to assess your child’s growth and determine whether he or she has a dwarfism-related disorder. Diagnostic tests may include:

• Measurements. A regular part of a well-baby medical exam is the measurement of height, weight and head circumference. At each visit, your pediatrician will plot these measurements on a chart to show your child’s current percentile ranking for each one. This is important for identifying abnormal growth, such as delayed growth or a disproportionately large head. If any trends in these charts are a concern, your pediatrician may make more-frequent measurements.
• Appearance. Many distinct facial and skeletal features are associated with each of several dwarfism disorders. Your child’s appearance also may help your pediatrician to make a diagnosis.
• Imaging technology. Your doctor may order imaging studies, such as X-rays, because certain abnormalities of the skull and skeleton can indicate which disorder your child may have. Various imaging devices may also reveal delayed maturation of bones, as is the case in growth hormone deficiency. A magnetic resonance imaging (MRI) scan may reveal abnormalities of the pituitary gland or hypothalamus, both of which play a role in hormone function.
• Genetic tests. Genetic tests are available for many of the known causal genes of dwarfism-related disorders, but these tests often aren’t necessary to make an accurate diagnosis. Your doctor is likely to suggest a test only to distinguish among possible diagnoses when other evidence is unclear or as a part of further family planning. If your pediatrician believes your daughter may have Turner syndrome, then a special lab test may be done that assesses the X chromosomes extracted from blood cells.
• Family history. Your pediatrician may take a history of stature in siblings, parents, grandparents or other relatives to help determine whether the average range of height in your family includes short stature.
• Hormone tests. Your doctor may order tests that assess levels of growth hormone or other hormones that are critical for childhood growth and development.

TREATMENTS

Most dwarfism treatments don’t increase stature but may correct or relieve problems caused by complications.

Surgical treatments

Surgical procedures that may correct problems in people with disproportionate dwarfism include:

• Correcting the direction in which bones are growing
• Stabilizing and correcting the shape of the spine
• Increasing the size of the opening in bones of the spine (vertebrae) to alleviate pressure on the spinal cord
• Placing a shunt to remove excess fluid around the brain (hydrocephalus), if it occurs

Limb lengthening

Some people with dwarfism choose to undergo surgery called extended limb lengthening. This procedure is controversial for many people with dwarfism because, as with all surgeries, there are risks. Because of the emotional and physical stress of multiple procedures, waiting until the person with dwarfism is old enough to participate in the decision to have the surgery is recommended.

Hormone therapy

For individuals with dwarfism due to growth hormone deficiency, treatment with injections of a synthetic version of the hormone may increase final height. In most cases, children receive daily injections for several years until they reach a maximum adult height — often within the average adult range for their family.

Treatment may continue throughout the teen years and early adulthood to ensure adult maturation, such as appropriate gain in muscle or fat. Some individuals may need lifelong therapy. The treatment may be supplemented with other related hormones if they are also deficient.

Treatment for girls with Turner syndrome also requires estrogen and related hormone therapy in order for them to begin puberty and achieve adult sexual development. Estrogen replacement therapy usually continues throughout life until a woman reaches the average age of menopause.

Growth hormone supplementation for children with achondroplasia does not increase final adult height.

Ongoing health care

Regular checkups and ongoing care by a doctor familiar with dwarfism can improve quality of life. Because of the range of symptoms and complications, treatments are tailored to address problems as they occur, such as assessment and treatment for ear infections, spinal stenosis or sleep apnea.

Adults with dwarfism should continue to be monitored and treated for problems that occur throughout life.