Dwarfism occurs when a person is unusually short. Dwarfism itself is not a disease and, as a result, it has no single medical definition.
Different organizations define dwarfism according to various criteria. The advocacy group, Little People of America, define dwarfism as a condition that results in an adult height of less than 4 foot 10 inches.
Medically, a person is considered to have dwarfism when they have a condition that causes them to be very short. But society might consider a person to be a dwarf based on short stature alone.
Dwarfism has many different causes. Several of the causes of dwarfism can lead to other health problems, such as osteoarthritis.
Some conditions that cause dwarfism disrupt the hormones that enable the body to grow. Dwarfism can also be due to metabolic disorders or malnourishment.
A group of conditions called skeletal dysplasias is the most common cause of dwarfism.
Skeletal dysplasias cause the bones to grow abnormally, resulting in a small stature. This abnormal growth can also result in uneven growth that produces a body of unusual proportions.
Typically, skeletal dysplasias are genetic conditions. Most people with skeletal dysplasias have parents of normal stature.
The three most common types of skeletal dysplasias are achondroplasia, spondyloepiphyseal dysplasia congenita, and diastrophic dysplasia.
Early in childhood, much of the cartilage a person is born with transforms into harder bone. In achondroplasia, this process does not happen as effectively.
Achondroplasia primarily affects the bones of the arms and legs. Achondroplasia is a genetic disorder present at birth. Its symptoms include:
- a normal-sized torso
- very short arms and legs, which may be difficult to move
- a large forehead
Some people with achondroplasia develop bone issues, such as scoliosis, have difficulty breathing, or suffer from a narrowing of the spine called spinal stenosis.
A rare form of achondroplasia occurs when people inherit two copies of a mutated gene that causes achondroplasia. This leads to very short bones and a poorly-developed rib cage. Most people with this disorder are stillborn or die in infancy because they cannot breathe.
Spondyloepiphyseal dysplasia congenita
Spondyloepiphyseal dysplasia congenita (SEDc) is a genetic mutation that causes a short torso, short arms, and short legs.
The spine, arms, and legs of people with this condition do not grow as expected. This makes them very short, but produces hands, feet, and a head of typical size.
In addition to a short stature, people with SEDc may experience a range of health problems, including:
- spine and hip issues
- foot deformities
- cleft palate
- joint diseases
SEDc may change the shape of the face, making the facial bones look flat.
Diastrophic dysplasia is the result of a gene mutation. It affects cartilage and bone development, causing very short arms and legs and a short stature.
People with this condition commonly have spine deformities and a condition called hitchhiker’s thumb that changes the shape of the thumbs.
People with diastrophic dysplasia often develop joint pain and mobility issues in childhood. They may have scoliosis, clubfoot, or difficulty moving.
Diastrophic dysplasia can cause breathing problems, particularly in childhood. Some children with this condition die of respiratory problems.
Other types of dwarfism
Other causes of dwarfism may be due to:
- organ failure that undermines the body’s ability to produce hormones or metabolize nutrients
- insufficient levels of certain hormones, particularly human growth hormone (HGH)
- malnourishment or lack of sufficient food, resulting in growth problems
These are all secondary causes of dwarfism. This means they are not genetic, and may be reversible with early detection and prompt treatment.
The most common forms of dwarfism, which are caused by genetic abnormalities of the skeleton and cartilage, may be detected through genetic testing when a fetus is still developing.
Most doctors only perform these tests when there is a reason to believe a fetus is at risk when dwarfism runs in a family. Because most people with dwarfism have parents of normal height, the condition is not typically detected until after birth.
Skeletal dysplasias, the most common type of dwarfism, can usually be diagnosed shortly after birth. X-rays, genetic testing, and a physical exam are frequently enough to diagnose the condition.
Less common forms of dwarfism typically appear later in life. They may be more difficult to diagnose, particularly if a child has no other symptoms other than short stature.
Blood testing to measure HGH levels, testing to assess organ health, and a complete medical history typically reveals the cause.
Some metabolic and hormonal causes of dwarfism may be reversible. Injections with HGH, for example, can help people with a growth hormone deficiency grow to a normal height.
The most common causes of dwarfism, however, are not curable. Instead, treatments focus on managing the symptoms, including:
- surgery to correct abnormalities in the bones and spinal cord
- removing the tonsils or adenoids to make it easier to breathe
- spinal decompression surgery
- using a tube called a shunt to drain fluid from the brain
- lifestyle changes, such as exercise and weight loss
People with many forms of dwarfism are vulnerable to obesity. Additional weight can increase their risk of heart problems.
People with dwarfism may need help with related medical conditions, such as osteoarthritis. Nevertheless, very short people can and do lead normal lives.
Many people with dwarfism say that the most difficult part of their condition is the stigma it carries. This stigma may include bullying and employment discrimination, as well as the use of negative terms like “midget.”
Because people with dwarfism have special medical needs, most need regular consultations with a team of doctors, including bone and cartilage specialists. However, with management of symptoms, it is possible for a person with dwarfism to live a long and healthy life.
Dwarfism does not have to be viewed as a disabling condition. The TLC show, Little People, Big World, shares the stories of people with dwarfism leading typical lives.
Treating dwarfism as a disability may make very short people feel stigmatized.