What is Dwarfism?

Dwarfism is when a person is short in stature due to their genes or medical reasons.

There are two broad categories of dwarfism: disproportionate and proportional.

Disproportionate dwarfism is characterized by a medium torso and shorter arms and legs, or a shortened torso with longer limbs.

With proportional dwarfism, the body parts are proportional, but shortened.

Symptoms of Dwarfism

In addition to short stature, dwarfism has many other symptoms, which can vary depending on its type.

Symptoms of disproportionate Dwarfism

Disproportionate dwarfism usually does not affect intellectual development unless the child has other rare conditions, including hydrocephalus or excess fluid around the brain.

Symptoms of disproportionate dwarfism may include:

Adults typically are about 122 cm tall
Average-size torso and very short limbs, especially in the upper halves of arms and legs
Short fingers
Wide spaces between the middle and ring fingers
Limited elbow mobility
Disproportionately large head
Prominent forehead
Flattened bridge of the nose
Bowing of legs that progressively worsens over time
Swaying of the back that progressively worsens over time

Some people with disproportionate dwarfism have a rare condition called congenital spondyloepiphyseal dysplasia. Adults with congenital spondyloepiphyseal dysplasia are 92 to 122 cm tall and may also have the following features:

Very short trunk
Short neck, arms, and legs, but average-size hands and feet
Broad chest
Flattened cheekbones
Cleft palate, or an opening in the roof of the mouth
Unstable neck bones
Deformed hips where the thigh bones turn inward
Twisted feet
Hunched upper back that progressively worsens
Swayed lower back that progressively worsens
Arthritis
Joint mobility problems
Impaired vision or hearing

Symptoms of proportional Dwarfism

Proportional dwarfism is caused by a disorder you have at birth or develop during childhood that interferes with growth and development. A common cause is too little growth hormone produced by the pituitary gland.

Symptoms of proportionate dwarfism include a smaller head, arms and legs. But everything is proportional to each other. Organ systems may also be smaller.

Other signs of proportional dwarfism in children are:

Slower growth rate than expected for their age
Height lower than the third percentile on standard charts for age
Delayed or no sexual development during the teen years

Causes of Dwarfism

There are about 400 types of dwarfism. Causes of proportionate dwarfism include metabolic and hormonal disorders such as growth hormone deficiency.

The most common types of dwarfism, called skeletal dysplasias, are genetic. Skeletal dysplasias are conditions of abnormal bone growth that cause disproportionate dwarfism.

They include:

Achondroplasia. The most common form of dwarfism, accounting for 70% of cases, achondroplasia occurs in about one in every 26,000 to 40,000 children and is present at birth. People with achondroplasia have a relatively long torso and short upper arms and legs. Other signs of achondroplasia include:

A large head with a prominent forehead
A flattened bridge of the nose
Protruding jaw
Crowded and misaligned teeth
Forward curvature of the lower spine
Bowed legs
Flat, short, broad feet
"Double-jointedness"

Spondyloepiphyseal dysplasia. A less common form of dwarfism, spondyloepiphyseal dysplasia affects about one in 95,000 children. Spondyloepiphyseal dysplasia refers to a group of conditions characterized by a shortened trunk that may not become apparent until the child is 5 to 10 years old. Other features may include:

Club feet
Cleft palate
Severe osteoarthritis in the hips
Weak hands and feet
Barrel-chested appearance

Diastrophic dysplasia. A rare form of dwarfism, diastrophic dysplasia, occurs in about one in 100,000 newborns. People with it tend to have shortened forearms and calves (this is called mesomelic shortening).

Other signs may include

Deformed hands and feet
Limited range of motion
Cleft palate
Ears with a cauliflower appearance

Turner syndrome. This genetic disorder only affects women. It is caused by the absence or partial X chromosome. Girls with Turner syndrome inherit only one fully functioning X chromosome from their parents, not one from each parent.

Genetic Dwarfism

Skeletal dysplasia is caused by a genetic mutation. A gene mutation can occur spontaneously or be inherited.
Diastrophic dysplasia and spondyloepiphyseal dysplasia in general are recessively hereditary. This means that a child must receive two copies of the mutated gene - one from the mother, one from the father - in order to get the disease.
Achondroplasia, on the other hand, is predominantly hereditary. This means that a child only needs one copy of the mutated gene to have this form of skeletal dysplasia. With a probability of 25%, a child born to a couple in which both parents are sick with achondroplasia will be of normal growth. But there is also a 25% chance that the child will inherit both genes for dwarfism, a condition known as dual dominance syndrome. This is a fatal disease that usually results in miscarriage.

Often the parents of children with achondroplasia do not themselves carry the mutated gene. Mutation in children occurs spontaneously at the time of conception.

Doctors don't know what causes the gene to mutate. This is a seemingly random event that can occur with any pregnancy. When parents of average height have a child with dwarfism due to a spontaneous mutation, it is unlikely that other children will also have the mutation.

In addition to genetic skeletal dysplasia, short stature has other causes, including pituitary disorders that affect growth and metabolism; kidney disease; and problems affecting the body's ability to absorb nutrients.

Diagnosis of Dwarfism

Some forms of dwarfism present in utero, at birth, or during infancy and can be diagnosed with x-rays and a physical examination. The diagnosis of achondroplasia, diastrophic dysplasia, or spondyloepiphyseal dysplasia can be confirmed by genetic testing. In some cases, prenatal tests are done if there are concerns about certain conditions.

Sometimes dwarfism only becomes apparent later in the child's life, when the signs of dwarfism force the parents to seek a diagnosis. Here are the signs and symptoms to look for in children that indicate the possibility of dwarfism:

A larger head
Late development of certain motor skills, such as sitting up or walking
Breathing problems
Curvature of the spine
Bowed legs
Joint stiffness and arthritis
Lower back pain numbness in the legs
Crowding of teeth

Doctors may also use these tests to diagnose dwarfism:

Appearance. Children with dwarfism may have changes in the skeleton or structures of the face as they develop.
Chart comparisons. During regular checkups, your child's height, weight, and head circumference will be measured and compared to standard developmental percentiles for their age. If your child is showing signs of abnormal growth, they may need more frequent measurements.
Imaging. Doctors may look for signs of achondroplasia, such as shorter limbs, or other causes of dwarfism on a fetal ultrasound scan during pregnancy. X-rays of infants or children may show that their arms or legs are not growing at a normal rate, or that their skeleton has signs of dysplasia. An MRI can show abnormalities in the pituitary or hypothalamus that affect hormone production.
Genetic test. DNA tests may be done before or after birth to look for genetic mutations associated with dwarfism. Girls with suspected Turner syndrome may need DNA testing to check their X chromosomes. DNA testing can help parents with family planning if they want to have more children.
History of the family. Pediatricians may test the height and height of other family members, such as siblings, to compare them to the child suspected of having dwarfism.
Hormonal analyses. Testing growth hormone levels can confirm if it is low.

Treatment of Dwarfism

Early diagnosis and treatment can help prevent or alleviate some of the problems associated with dwarfism. People with growth hormone deficiency dwarfism can be treated with growth hormone.

In many cases, people with dwarfism experience orthopedic or medical complications. Treatment for them may include:

Insertion of a shunt to drain excess fluid and relieve pressure on the brain
A tracheotomy to improve breathing through small airways
Corrective surgeries for deformities such as cleft palate, club foot, or bowed legs
Surgery to remove tonsils or adenoids to improve breathing problems related to large tonsils, small facial structures, and/or a small chest
Surgery to widen the spinal canal (the opening through which the spinal cord passes) to relieve spinal cord compression
Extended limb lengthening, a controversial surgery, due in part to its risks, it involves several procedures. It is only done on adults.
Other treatment may include:
Physical therapy to strengthen muscles and increase joint range of motion
Back braces to improve curvature of the spine
Placement of drainage tubes in the middle ear to help prevent hearing loss due to repeated ear infections
Orthodontic treatment to relieve crowding of teeth caused by a small jaw
Nutritional guidance and exercise to help prevent obesity, which can aggravate skeletal problems

Complications of Dwarfism

Disproportionate dwarfism leads to changes in limbs, back and head size, which can lead to such complications:

Arthritis
Back pain or breathing difficulties due to hunched or swayed back
Bowed legs
Crowded teeth
Delayed motor skills development
Frequent ear infections and possibly hearing loss
Hydrocephalus (fluid on the brain)
Pressure on the spine at the base of the skull
Sleep apnea
Spinal stenosis, a narrowing of the spine that may cause leg pain or numbness
Weight gain that may cause back problems

Proportional dwarfism can cause you to have smaller or less developed organs. Girls with Turner syndrome may have heart problems. Children with lower growth hormone levels or Turner syndrome may have emotional or social problems due to delayed sexual development.

Women with disproportionate dwarfism may have pregnancy complications such as breathing problems. They almost always have to give birth by caesarean section because the shape of their pelvis makes vaginal delivery too difficult.

Anyone with dwarfism can encounter people who insult them or misunderstand their condition. Children with dwarfism and low self-esteem may need emotional support from their parents to deal with their feelings.