Nanism: Signs, Symptoms, Causes, Diagnosis, Classification, Prevention and Treatment

Also known as dwarfism or short stature, it occurs when an organism is extremely small.

In humans, it is sometimes defined as an adult height of less than 4 feet 10 inches (58 inches; 147 cm), regardless of gender, although some people with nanism are slightly taller.

Disproportionate nanism is characterized by short limbs or a short torso. In cases of proportional nanism, both the limbs and torso are unusually small. Normal intelligence and life expectancy are common.

Treatment depends on the underlying cause. People with bone growth disorders can sometimes be treated with surgery or physical therapy.

Hormonal disorders can also be treated with hormone replacement therapy before the child’s growth plates fuse. Individual accommodations, such as specialty furniture, are often used by people with nanism.

Many support groups provide services to help people and the discrimination they may face. In addition to the medical aspect of the condition, there are also social aspects. For a person with nanism, height discrimination can lead to ridicule in childhood and discrimination in adulthood.

In the United Kingdom, United States, Canada, Australia, and other English-speaking countries, some people with nanism prefer to be called dwarfs, small people, or people of short stature.

Historically, the term “dwarf” was used to describe proportional dwarfs; however, this term is considered offensive by some.

Signs and symptoms of nanism

A defining characteristic of nanism is an adult height less than the 2.3 percentile of the standard growth charts. There may be no complications outside of fitting your size.

Short stature is a common replacement for the term “nanism”, especially in a medical context. Short stature is clinically defined as height within the shortest 2.3% of the general population.

However, those with mild skeletal dysplasias may not be affected by nanism. In some cases of untreated hypochondroplasia, males grow up to 5 feet 5 inches. Although it is short in relative context, it does not fall into the extreme ranges of the growth charts.

Disproportionate nanism is characterized by shortened limbs or a shortened torso. Facial features are often affected and individual parts of the body may have problems associated with them.

Spinal stenosis, ear infection, and hydrocephalus are common. In spinal dysostosis, one has a small trunk, with limbs of average size.

Proportional nanism is marked by a short torso with short limbs, leading to significantly below average height. Sexual development is often delayed or impaired in adulthood. This type of nanism is caused by an endocrine disorder and not by skeletal dysplasia.

The physical effects of bones involve joint pain caused by abnormal bone alignment or nerve compression. Early degenerative joint disease, exaggerated lordosis or scoliosis, and constriction of the spinal cord or nerve roots can cause pain and disability.

There are syndromes that can affect the cranial structure and brain growth, severely affecting mental capacity. Unless the brain is directly affected by the underlying disorder, there is little or no chance of mental impairment that can be attributed to nanism.

The psychosocial limitations of society can be more disabling than physical symptoms, especially in childhood and adolescence, but people with nanism vary greatly in the degree to which social participation and emotional health are affected.

Social biases against extreme incoordination can reduce marriage and social opportunities.

Numerous studies have shown reduced employment opportunities. Lack of seriousness is associated with lower income. Self-esteem can suffer and family relationships can suffer.

Extreme thinness (in the low range of 2-3 feet [60-90 cm]) can interfere with activities of daily living, such as driving or using countertops built for taller people.

Other common attributes of nanism such as bowed knees and unusually short fingers can lead to back problems and difficulty walking and handling objects.

Causes

Nanism can be the result of many medical conditions, each with its own symptoms and causes. Extreme shortness of stature in humans with proportional body parts usually has a hormonal cause, such as growth hormone deficiency , once called pituitary nanism.

Two disorders, achondroplasia and growth hormone deficiency, are responsible for most cases of human nanism.

Acondroplasia

The most recognizable and common form of nanism in humans is achondroplasia, which accounts for 70% of cases of nanism, and occurs between 4 and 15 out of every 100,000 live births. It produces short rhizomelic limbs, increased spinal curvature, and distortion of skull growth.

In achondroplasia, the extremities of the body are proportionally shorter than the trunk (abdominal area), with a larger than average head and characteristic facial features.

Achondroplasia is an autosomal dominant disorder caused by the presence of a defective allele in the genome. If there are a pair of achondroplasia alleles, the result is fatal. Achondroplasia is a mutation in fibroblast growth factor receptor 3.

In the context of achondroplasia, this mutation causes FGFR3 to become constitutively active, inhibiting bone growth.

Research by urologist Harry Fisch of the Columbia Presbyterian Hospital Center for Male Reproduction indicates that in humans this defect can be inherited exclusively from the father and becomes more and more likely with paternal age: specifically males that reproduce after 35 years.

Growth hormone deficiency

Growth hormone deficiency (DHC) is a medical condition in which the body produces insufficient growth hormone. Laron’s syndrome (insensitivity to growth hormone) is another cause. Those with growth hormone problems tend to be proportionate.

Other

Other causes of nanism include congenital spondyloepiphyseal dysplasia, diastrophic dysplasia, pseudoachondroplasia, hypochondroplasia, Noonan syndrome, primordial nanism, Turner syndrome, osteogenesis imperfecta (OI), and hypothyroidism .

Severe brevity with skeletal distortion also occurs in some of the mucopolysaccharidoses and other storage disorders. The hypogonadism hypogonadism can cause a proportionate dwarfism, albeit temporary.

Serious chronic diseases can cause nanism as a side effect. Harsh environmental conditions, such as malnutrition, can also produce nanism.

These types of nanism are indirect consequences of the generally unhealthy or malnourished condition of the individual, and not of a specific disease. Nanism often takes the form of simple short stature, without any deformity, leading to proportional nanism.

In societies where poor nutrition is widespread, the average height of the population can be reduced below its genetic potential due to a lack of adequate nutrition. Sometimes there is no definitive cause for short stature.

Nanism diagnosis

Nanism is often diagnosed in childhood on the basis of visible symptoms. Generally, a physical exam can be sufficient to diagnose certain types of nanism, but genetic testing and diagnostic imaging can be used to determine the exact condition.

In a person’s youth, height-tracking growth charts can be used to diagnose subtle forms of nanism that have no other surprising physical characteristics. Short stature or stunted growth during youth is often what brings the condition to medical attention.

Skeletal dysplasia is usually suspected due to obvious physical characteristics (for example, unusual face configuration or skull shape), due to an obviously affected parent, or because of body measurements (arm width, upper-to-lower segment ratio) indicate disproportion.

Bone X-rays are often key to diagnosing a specific skeletal dysplasia, but they are not the only diagnostic tool.

Most children with suspected skeletal dysplasias are referred to a genetics clinic for diagnostic confirmation and genetic counseling. Since about 2000, genetic testing for some of the specific disorders has been available.

During an initial medical evaluation for shortening, the absence of disproportion and other clues listed above generally indicate causes other than bone dysplasias.

Classification

In men and women, the only requirement to be considered a dwarf is to have an adult height of less than 147 cm (4 feet 10 inches) and it is almost always classified with respect to the underlying condition that is the cause of the short stature.

Nanism is generally caused by a genetic variant; the achondroplasia is caused by a mutation on chromosome 4. If the dwarfism is caused by a medical disorder, the person is derived by the underlying disorder diagnosed.

Disorders that cause nanism are often classified by proportionality. Disproportionate nanism describes disorders that cause unusual proportions of body parts, while proportionate nanism results in generally uniform growth retardation of the body.

Disorders that cause nanism can be classified according to one of hundreds of names, which are generally permutations of the following roots:

Location

  • Rhizomelic:  for example, bones of the upper arm or thigh.
  • Mesomelic –  For example, bones of the forearm or lower leg.
  • Acromelic:  for example, bones of the hands and feet.
  • Micromelico : full limbs are shortened.

Source

  • Chondro : of cartilage.
  • Osteo : bone.
  • Spondylosis : of the vertebrae.
  • Plasia : form.
  • Trophy : growth.

Examples include achondroplasia and chondrodystrophy.

Prevention

Many types of nanism are currently impossible to prevent because they are genetically caused. The genetic conditions that cause nanism can be identified with genetic testing, by detecting the specific variations that lead to the disease.

However, due to the number of causes of nanism, it may be impossible to definitively determine whether a child will be born with nanism.

Nanism resulting from malnutrition or a hormonal abnormality can be treated with an appropriate diet or hormonal therapy. Growth hormone deficiency can be remedied by injections of human growth hormone (HCH) during the first few years of life.

Treatment

The genetic mutations of most forms of nanism caused by bone dysplasia cannot yet be altered, so therapeutic interventions generally aim to prevent or reduce pain or physical disability, increase adult height, or mitigate stresses. psychosocial and improve social adaptation.

Forms of nanism associated with the endocrine system can be treated with hormone therapy. If the cause is prepubertal growth hormone hyposecretion, supplemental growth hormone can correct the abnormality.

If the growth hormone receptor is affected, the condition can be more difficult to treat. Hypothyroidism is another possible cause of nanism that can be treated with hormone therapy.

Thyroid hormone injections can mitigate the effects of the condition, but the lack of proportion can be permanent.

Pain and disability can be improved with physical therapy, braces or other orthopedic devices, or through surgical procedures.

The only simple interventions that increase an adult’s perceived height are clothing enhancements, such as shoe lifts or hairstyling.

Growth hormone is rarely used for dyspnea caused by bone dysplasias, as the benefit of height is typically small (less than 5 cm) and the cost is high.

The most effective means of increasing adult height by several inches is distraction osteogenesis, although availability is limited and the cost is high in terms of money, discomfort, and disruption of life.

Most people with nanism do not choose this option, and it remains controversial. For other types of nanism, surgical treatment is not possible.

Society and culture

Terminology

The appropriate term to describe a person of particularly short stature (or with the genetic condition achondroplasia) has been historically ambiguous, and has evolved euphemistically in recent centuries.

The noun dwarf comes from Old English, which originally referred to a being from Germanic mythology (a dwarf) that inhabits mountains and on land, and is associated with wisdom, blacksmithing, mining, and crafts.

The etymology of the word dwarf is contested, and scholars have proposed varied theories about the origins of being, including that dwarves may have originated as spirits of nature or as beings associated with death, or as a mixture of concepts.

The coincident etymologies include a base on the Indo-European root * dheur- (meaning “harm”), the Indo-European root * dhreugh (from which the modern German “dream” Traum and Trug’s “delusion” come), and have been made comparisons to the Old Indian dhvaras (a type of demonic being).

The being may not have gained associations with small stature until a later period. The terms “dwarf,” “little person,” and “short person” are now generally accepted by most people affected by these disorders.

The English word ‘Midget’, whose etymology indicates a ‘little biting insect’, rose to prominence in the mid-19th century after Harriet Beecher Stowe used it in her novels Sunny Memories of Foreign Lands and Old Town Folks where she described children and an extremely short man, respectively.

Later, some short people found the word offensive because it was the descriptive term for PT Barnum’s dwarves, who were used for public amusement during the monster show era.

It is also not considered accurate, as it is not a medical term or diagnosis, although it is sometimes used as a slang term to describe those who are particularly short, whether or not they have nanism.

Nanism and sport

Dwarves are supported to compete in sport by a number of organizations nationally and internationally.

The Dwarf Athletic Association of America and the UK Dwarf Sports Association provide opportunities for dwarves to compete nationally and internationally in America and Europe, respectively.

The UK Midget Sports Association organizes between 5 and 20 events per month for athletes with restricted growth conditions in the UK.

For example, swimming and cycling are often recommended for people with skeletal dysplasias, since those activities put minimal pressure on the spine.

Art and media representations

In art, literature, and film, dwarfs are rarely depicted as ordinary people, who are very short, but rather as a species apart.

Novelists, artists, and filmmakers may attribute a special moral or aesthetic significance to their “isolation” or deformity.

Artistic representations of nanism can be found in Greek vases and other ancient artifacts, including ancient Egyptian art in which dwarves have likely been viewed as a divine manifestation, with records indicating that they could reach high positions in society.

The Hindu text Bhagavat Purana dedicates nine chapters to the adventures of Vamana, a dwarf avatar of Lord Vishnu.

Representations of nanism are also found in European paintings and in many illustrations. Many European (especially Spanish) paintings from the 16th-19th centuries depict dwarves by themselves or with others.

In the Talmud, the second son born to the Egyptian pharaoh of the Bible is said to be a dwarf. Recent studies have suggested that the ancient Egyptians held dwarves in high regard.

Several important mythological figures of the North American nation Wyandot are portrayed as dwarfs. As popular media has become mainstream, the number of works depicting dwarves has increased dramatically.

Nanism is depicted in many books, movies, and television series such as:

  • Willow con Warwick Davis.
  • The Man with the Golden Revolver (and later parodied in Austin Powers).
  • Gulliver’s Travels by Jonathan Swift.
  • Little land in the movie “The Wizard of Oz.”
  • The Oompa Loompa in the movie “Willy Wonka and the Chocolate Factory.”
  • Tony Cox in the movie “Bad Santa.”
  • The reality show series “A great little world”.
  • What a couple, reality show on the TLC channel.
  • A Song of Ice and Fire (and its television adaptation “Game of Thrones”).

The Tin Drum by Günter Grass, the short made the reality show The Littlest Groom, and the film The Station Agent.

The Animal Planet TV series Pit Boss features midget actor Shorty Rossi and his talent agency, “Shortywood Productions,” which Rossi uses to provide funding for his pit bull rescue operation, “Shorty’s Rescue.”

Rossi’s three full-time employees, featured on the series, are small people and aspiring actors.

In September 2014, Creative Business House, together with Donnons Leur Une Chance, created the Dwarf International Fashion Show to raise awareness and increase the confidence of people living with nanism.