Dwarfism, also known as short stature, occurs when an organism is extremely small. In humans, it is sometimes defined as an adult height of less than 147 centimetres (4 ft 10 in), regardless of sex, although some individuals with dwarfism are slightly taller. Disproportionate dwarfism is characterized by either short limbs or a short torso. In cases of proportionate dwarfism, both the limbs and torso are unusually small. Normal intelligence and lifespan are usual.
Treatment depends on the underlying cause. Those with bone growth disorders can sometimes be treated with surgery, or physical therapy. Hormone disorders can also be treated with hormone replacement therapy before the child's growth plates fuse. Individual accommodations, such as specialized furniture, are often used by people with dwarfism. Many support groups provide services to aid individuals and the discrimination they may face.
In addition to the medical aspect of the condition, there are also social aspects. For a person with dwarfism, 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 dwarfism prefer to be called dwarfs, little people, or persons of short stature. Historically, the term "midget" was used to describe proportionate dwarfs; however, this term is now regarded as offensive by some.
|A man with dwarfism|
|Specialty||Endocrinology, medical genetics|
|Causes||Hypo secretion of Growth Hormone from Pituitary gland (Growth Hormone deficiency)|
A defining characteristic of dwarfism is an adult height less than the 2.3rd percentile of the CDC standard growth charts. There is a wide range of physical characteristics. Variations in individuals are identified by diagnosing and monitoring the underlying disorders. There may not be any complications outside adapting to their size.
Short stature is a common replacement of the term 'dwarfism', especially in a medical context. Short stature is clinically defined as a height within the lowest 2.3% of those in the general population. However, those with mild skeletal dysplasias may not be affected by dwarfism. In some cases of untreated hypochondroplasia, males grow up to 5 feet 5 inches. Though that is short in a relative context, it does not fall into the extreme ranges of the growth charts.
Disproportionate dwarfism is characterized by shortened limbs or a shortened torso. In achondroplasia one has an average-sized trunk with short limbs and a larger forehead. Facial features are often affected and individual body parts may have problems associated with them. Spinal stenosis, ear infection, and hydrocephalus are common. In case of spinal dysostosis, one has a small trunk, with average-sized limbs.
Proportionate dwarfism is marked by a short torso with short limbs, thus leading to a height that is significantly below average. There may be long periods without any significant growth. Sexual development is often delayed or impaired into adulthood. This dwarfism type is caused by an endocrine disorder and not a skeletal dysplasia.
Physical effects of malformed bones vary according to the specific disease. Many involve joint pain caused by abnormal bone alignment, or from nerve compression. Early degenerative joint disease, exaggerated lordosis or scoliosis, and constriction of spinal cord or nerve roots can cause pain and disability. Reduced thoracic size can restrict lung growth and reduce pulmonary function. Some forms of dwarfism are associated with disordered function of other organs, such as the brain or liver, sometimes severely enough to be more of an impairment than the unusual bone growth.
Mental effects also vary according to the specific underlying syndrome. In most cases of skeletal dysplasia, such as achondroplasia, mental function is not impaired. However, there are syndromes which can affect the cranial structure and growth of the brain, severely impairing mental capacity. Unless the brain is directly affected by the underlying disorder, there is little to no chance of mental impairment that can be attributed to dwarfism.
The psycho-social limitations of society may be more disabling than the physical symptoms, especially in childhood and adolescence, but people with dwarfism vary greatly in the degree to which social participation and emotional health are affected.
Dwarfism can result from many medical conditions, each with its own separate symptoms and causes. Extreme shortness in humans with proportional body parts usually has a hormonal cause, such as growth-hormone deficiency, once called pituitary dwarfism. Two disorders, achondroplasia and growth hormone deficiency, are responsible for the majority of human dwarfism cases.
It produces rhizomelic short limbs, increased spinal curvature, and distortion of skull growth. In achondroplasia the body's limbs are proportionately shorter than the trunk (abdominal area), with a larger head than average and characteristic facial features. Achondroplasia is an autosomal dominant disorder caused by the presence of a faulty allele in the genome. If a pair of achondroplasia alleles are present, the result is fatal. Achondroplasia is a mutation in the 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 Male Reproductive Center at Columbia Presbyterian Hospital indicates that in humans this defect may be exclusively inherited from the father and becomes increasingly probable with paternal age: specifically males reproducing after 35.
Growth hormone deficiency (GHD) is a medical condition in which the body produces insufficient growth hormone. Growth hormone, also called somatotropin, is a polypeptide hormone which stimulates growth and cell reproduction. If this hormone is lacking, stunted or even halted growth may become apparent. Children with this disorder may grow slowly and puberty may be delayed by several years or indefinitely. Growth hormone deficiency has no single definite cause. It can be caused by mutations of specific genes, damage to the pituitary gland, Turner's syndrome, poor nutrition, or even stress (leading to psychogenic dwarfism). Laron syndrome (growth hormone insensitivity) is another cause. Those with growth hormone issues tend to be proportionate.
Other causes of dwarfism are spondyloepiphyseal dysplasia congenita, diastrophic dysplasia, pseudoachondroplasia, hypochondroplasia, Noonan syndrome, primordial dwarfism, Turner syndrome, osteogenesis imperfecta (OI), and hypothyroidism. Severe shortness with skeletal distortion also occurs in several of the Mucopolysaccharidoses and other storage disorders. Hypogonadotropic hypogonadism may cause proportionate, yet temporary, dwarfism.
Serious chronic illnesses may produce dwarfism as a side effect. Harsh environmental conditions, such as malnutrition, may also produce dwarfism. These types of dwarfism are indirect consequences of the generally unhealthy or malnourished condition of the individual, and not of any specific disease. The dwarfism often takes the form of simple short stature, without any deformities, thus leading to proportionate dwarfism. In societies where poor nutrition is widespread, the average height of the population may be reduced below its genetic potential by the lack of proper nutrition. Sometimes there is no definitive cause of short stature.
Dwarfism is often diagnosed in childhood on the basis of visible symptoms. A physical examination can usually suffice to diagnose certain types of dwarfism, but genetic testing and diagnostic imaging may be used to determine the exact condition. In a person's youth, growth charts that track height can be used to diagnose subtle forms of dwarfism that have no other striking physical characteristics.
Short stature or stunted growth during youth is usually what brings the condition to medical attention. Skeletal dysplasia is usually suspected because of obvious physical features (e.g., unusual configuration of face or shape of skull), because of an obviously affected parent, or because body measurements (arm span, upper to lower segment ratio) indicate disproportion. Bone X-rays are often key to diagnosing a specific skeletal dysplasia, but are not the sole diagnostic tool. Most children with suspected skeletal dysplasias are referred to a genetics clinic for diagnostic confirmation and genetic counseling. Since about the year 2000, genetic tests for some of the specific disorders have become available.
During an initial medical evaluation of shortness, the absence of disproportion and other clues listed above usually indicates causes other than bone dysplasias.
In men and women, the sole requirement for being considered a dwarf is having an adult height under 147 cm (4 ft 10 in) and it is almost always classified with respect to the underlying condition that is the cause of the short stature. Dwarfism is usually caused by a genetic variant; achondroplasia is caused by a mutation on chromosome 4. If dwarfism is caused by a medical disorder, the person is referred to by the underlying diagnosed disorder. Disorders causing dwarfism are often classified by proportionality. Disproportionate dwarfism describes disorders that cause unusual proportions of the body parts, while proportionate dwarfism results in a generally uniform stunting of the body.
Disorders that cause dwarfism may be classified according to one of hundreds of names, which are usually permutations of the following roots:
Many types of dwarfism are currently impossible to prevent because they are genetically caused. Genetic conditions that cause dwarfism may be identified with genetic testing, by screening for the specific variations that result in the condition. However, due to the number of causes of dwarfism, it may be impossible to determine definitively if a child will be born with dwarfism.
Dwarfism resulting from malnutrition or a hormonal abnormality may be treated with an appropriate diet or hormonal therapy. Growth hormone deficiency may be remedied via injections of human growth hormone (HGH) during early life.
Genetic mutations of most forms of dwarfism caused by bone dysplasia cannot be altered yet, so therapeutic interventions are typically aimed at preventing or reducing pain or physical disability, increasing adult height, or mitigating psychosocial stresses and enhancing social adaptation.
Forms of dwarfism associated with the endocrine system may be treated using hormonal therapy. If the cause is prepubescent hyposecretion of growth hormone, supplemental growth hormone may correct the abnormality. If the receptor for growth hormone is itself affected, the condition may prove harder to treat. Hypothyroidism is another possible cause of dwarfism that can be treated through hormonal therapy. Injections of thyroid hormone can mitigate the effects of the condition, but lack of proportion may be permanent.
Pain and disability may be ameliorated by physical therapy, braces or other orthotic devices, or by surgical procedures. The only simple interventions that increase perceived adult height are dress enhancements, such as shoe lifts or hairstyle. Growth hormone is rarely used for shortness caused by bone dysplasias, since the height benefit is typically small (less than 5 cm [2 in]) and the cost high. The most effective means of increasing adult height by several inches is distraction osteogenesis, though availability is limited and the cost is high in terms of money, discomfort, and disruption of life. Most people with dwarfism do not choose this option, and it remains controversial. For other types of dwarfism, surgical treatment is not possible.
The appropriate term for describing a person of particularly short stature (or with the genetic condition achondroplasia) has historically been ambiguous, and has developed euphemistically over the past few centuries.
The noun dwarf stems from Old English dweorg, originally referring to a being from Germanic mythology—a dwarf—that dwells in mountains and in the earth, and is associated with wisdom, smithing, mining, and crafting. The etymology of the word dwarf is contested, and scholars have proposed varying theories about the origins of the being, including that dwarfs may have originated as nature spirits or as beings associated with death, or as a mixture of concepts. Competing etymologies include a basis in the Indo-European root *dheur- (meaning 'damage'), the Indo-European root *dhreugh (whence modern German Traum 'dream' and Trug 'deception'), and comparisons have been made with 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", "LP", and "person of short stature" are now generally considered acceptable by most people affected by these disorders. However, the plural "dwarfs" as opposed to "dwarves" is generally preferred in the medical context, possibly because the plural "dwarves" was popularized by author J.R.R. Tolkien, describing a race of characters in his The Lord of the Rings books resembling Norse dwarfs.
"Midget", whose etymology indicates a "tiny biting insect", came into 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 people of short stature considered the word to be offensive because it was the descriptive term applied to P. T. Barnum's dwarfs used for public amusement during the freak show era. It is also not considered accurate as it is not a medical term or diagnosis, though it is sometimes used as a slang term to describe those who are particularly short, whether or not they have dwarfism.
Dwarfs are supported to compete in sport by a number of organisations nationally and internationally.
The Dwarf Sports Association UK organises between 5 and 20 events per month for athletes with restricted growth conditions in the UK.
For instance, swimming and bicycling are often recommended for people with skeletal dysplasias, since those activities put minimal pressure on the spine.
Since its early days, professional wrestling has had the involvement of dwarf athletes. "Midget wrestling" had its heyday in the 1950s-70s, when wrestlers such as Little Beaver, Lord Littlebrook, and Fuzzy Cupid toured North America, and Sky Low Low was the first holder of the National Wrestling Alliance's World Midget Championship. In the following couple of decades, more wrestlers became prominent in North America, including foreign wrestlers like Japan's Little Tokyo. Although the term is seen by some as pejorative, many past and current midget wrestlers, including Hornswoggle, have said they take pride in the term due to its history in the industry and its marketability.
In art, literature, and movies, dwarfs are rarely depicted as ordinary people who are very short but rather as a species apart. Novelists, artists, and moviemakers may attach special moral or aesthetic significance to their "apartness" or misshapenness.
Artistic representations of dwarfism can be found on Greek vases and other ancient artifacts, including ancient Egyptian art in which dwarfs are likely to have been seen as a divine manifestation, with records indicating they could reach high positions in society.
Depictions of dwarfism are also found in European paintings and many illustrations. Many European paintings (especially Spanish) of the 16th–19th centuries depict dwarfs by themselves or with others. In the Talmud, it is said that the second born son of the Egyptian Pharaoh of the Bible was a dwarf. Recent scholarship has suggested that ancient Egyptians held dwarfs in high esteem. Several important mythological figures of the North American Wyandot nation are portrayed as dwarfs.
As popular media have become more widespread, the number of works depicting dwarfs have increased dramatically. Dwarfism is depicted in many books, films, and TV series such as Willow, The Wild Wild West, The Man with the Golden Gun (and later parodied in Austin Powers), Gulliver's Travels by Jonathan Swift, The Wizard of Oz, Willy Wonka & the Chocolate Factory, Bad Santa, A Son of the Circus, Little People Big World, The Little Couple, A Song of Ice and Fire (and its TV adaptation Game of Thrones), Seinfeld, The Orator, In Bruges, The Tin Drum by Günter Grass, the short-lived reality show The Littlest Groom, and the films The Station Agent and Zero.
The Animal Planet TV series Pit Boss features dwarf 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 in the series, are all little people and aspiring actors.
In September 2014, Creative Business House, along with Donnons Leur Une Chance, created the International Dwarf Fashion Show to raise awareness and boost self-confidence of people living with dwarfism.
Achondroplasia is a genetic disorder that results in dwarfism. In those with the condition, the arms and legs are short, while the torso is typically of normal length. Those affected have an average adult height of 131 centimetres (4 ft 4 in) for males and 123 centimetres (4 ft) for females. Other features include an enlarged head and prominent forehead. It does not affect intelligence.Achondroplasia is due to a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. In about 80% of cases this occurs as a new mutation during early development. In the other cases it is inherited from one's parents in an autosomal dominant manner. Those with two affected genes do not typically survive. Diagnosis is generally based on symptoms, but may be supported by genetic testing if uncertain.Treatments may include support groups and growth hormone therapy. Efforts to treat or prevent complications such as obesity, hydrocephalus, obstructive sleep apnea, middle ear infections, or spinal stenosis may be required. Life expectancy of those affected is about 10 years less than average. The condition affects about 1 in 27,500 people. Rates are higher in Denmark and Latin America. The shortest known adult with the condition is Jyoti Amge at 62.8 centimetres (2 ft 0.7 in).Ateliosis
Ateliosis or ateleiosis is a diagnosis used in the early 1900s to describe patients with short stature. Ateliosis literally means "failure to achieve perfection", and was used to describe proportional dwarfism. The term was popularised by Hastings Gilford, who used the term to refer to forms of dwarfism associated with and without sexual maturation.Ateliosis was reported as early as 1904 in relation to progeria, a syndrome of premature aging.According to the Merriam-Webster Dictionary it is, “dwarfism associated with anterior pituitary deficiencies and marked by essentially normal intelligence and proportions though often retarded sexual development”. The physical characteristics include: normal facial features, childlike high pitched voice, proportioned body, and abnormal genitalia. Their mental development is normal to slightly delayed. Hastings Gilford originated the term to describe patients with "continuous youth".Beetlejuice (entertainer)
Lester Green (born June 2, 1968), better known by his stage name "Beetlejuice", is an American actor and comedian with microcephaly and dwarfism, and a frequent guest on The Howard Stern Show. A member of Stern's Wack Pack, Beetlejuice was named the greatest Wack Packer of all time. Howard Stern has been quoted saying that Beetlejuice has been his best guest ever. Lester has appeared in feature films as well as performed voice-over work. Green has performed with various Howard Stern Show-related comedians, including those who perform under The Killers of Comedy Tour banner.Charla Baklayan Faddoul
Charla Baklayan Faddoul (born July 23, 1976) is an Armenian-American reality television personality who appeared on The Amazing Race 5 and The Amazing Race: All-Stars television shows. Charla was born with achondroplasia, the most common form of dwarfism, and is 4' (1.22 m) tall. Her partner on The Amazing Race was her cousin Mirna Hindoyan.Dwarf-tossing
Dwarf-tossing, also called midget-tossing, is a pub/bar attraction in which people with dwarfism, wearing special padded clothing or Velcro costumes, are thrown onto mattresses or at Velcro-coated walls. Participants compete to throw the person with dwarfism the farthest. A related formerly practiced activity was dwarf-bowling, in which a person with dwarfism was placed on a skateboard and used as a bowling ball. Dwarf Tossing was started in Australia as a form of pub entertainment in the early 1980s.Dwarf cat
A dwarf cat is any domestic cat which has the condition of dwarfism due to a genetic mutation. Unlike undersized cats of normal proportions, dwarf cats display symptoms of osteochondrodysplasia—genetic disorders of bone and cartilage, typically manifested as noticeably short legs.Since the mid-twentieth century, cat breeds with embedded dwarfism have been developed for commercial sale. The ethics of their selective breeding is hotly debated, and many countries prohibit it as cruelty to animals.Growth hormone deficiency
Growth hormone deficiency (GHD) is a medical condition due to not enough growth hormone (GH). Generally the most noticeable symptom is a short height. In newborns there may be low blood sugar or a small penis. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density.GHD can be present at birth or develop later in life. Causes may include genetics, trauma, infections, tumors, or radiation therapy. Genes that may be involved include GH1, GHRHR, or BTK. In a third of cases no cause is apparent. The underlying mechanism generally involves problems with the pituitary gland. Some cases are associated with a lack of other pituitary hormones, in which case it is known as combined pituitary hormone deficiency. Diagnosis involves blood tests to measure growth hormone levels.Treatment is by growth hormone replacement. The frequency of the condition is unclear. Most cases are initially noticed in children. The genetic forms are estimated to affect about 1 in 7,000 people. Most types occur equally in males and females though males are more often diagnosed.Insular dwarfism
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing. This process has occurred many times throughout evolutionary history, with examples including dinosaurs, like Europasaurus, and modern animals such as elephants and their relatives. This process, and other "island genetics" artifacts, can occur not only on islands, but also in other situations where an ecosystem is isolated from external resources and breeding. This can include caves, desert oases, isolated valleys and isolated mountains ("sky islands"). Insular dwarfism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies (island gigantism), and large species tend to evolve smaller bodies.Laron syndrome
Laron syndrome, or Laron-type dwarfism, is an autosomal recessive disorder characterized by an insensitivity to growth hormone (GH), usually caused by a mutant growth hormone receptor. It causes a short stature and an increased sensitivity to insulin which means that diabetes mellitus type 2 is less likely to develop, and possibly cancer as well. It can be treated with injections of recombinant IGF-1.Little People, Big World
Little People, Big World is an American reality television series that premiered on March 4, 2006, and airs on TLC. The series chronicles the lives of the six-member Roloff family farm near Portland, Oregon. Many of the episodes focus on the parents, Matt and Amy, and one of their children, Zach, who have dwarfism.
On August 26, 2010, TLC announced that the sixth season would be the last for the show. After its final season, TLC aired several specials: "Conquering Mount St. Helens", "Breaking Down the Walls", and "Welcome to the Jungle". On October 5, 2012, TLC announced a spin-off series – Little People Big World: Wedding Farm. It chronicles Matt and Amy as they jump-start their wedding business on the farm. The series premiered on November 13, 2012, and ran for six episodes.It was announced in October 2013 that Little People, Big World would return for a seventh season. Season seven consists of eight episodes, and premiered on October 29, 2013. An eighth season began on September 2, 2014, and a ninth season began on July 6, 2015. The show was renewed for a tenth season which premiered in fall 2016. As of 2018, the show has aired for 12 seasons. On March 13, 2018, TLC announced the show was renewed for a 14th season to premiere on April 2, 2019.Midget
Midget (from midge, a sand fly) is a term for a person of unusually short stature that is considered by some to be pejorative. While not a medical term, it has been applied to persons of unusually short stature, often with the medical condition dwarfism, particularly proportionate dwarfism.It may also refer to anything of much smaller than normal size, as a synonym for "miniature", such as a midget cell, a midget crabapple, a midget submarine, MG's Midget, Daihatsu's Midget, and the Midget Mustang airplane; or to anything that regularly uses anything that is smaller than normal (other than a person), such as midget car racing and quarter midget racing; or a smaller version of play or participation, such as midget golf; or to anything designed for very young (i.e., small) participants—in many cases children—such as Disneyland's Midget Autopia, Midget hockey, and Midget football.Miniature horse
Miniature horses are horses defined by their small height. They can be found in many nations, particularly in Europe and the Americas, and are the result of centuries of selective breeding. Depending on the particular breed registry involved, the height of these horses is usually less than 34–38 inches (86–97 cm) as measured at the last hairs of the mane, which are found at the withers. While miniature horses fit a height-based definition to be considered a very small pony, many retain horse characteristics and are considered "horses" by their respective registries. They have various colors and coat patterns.
Miniature horses are generally bred to be friendly and to interact well with people. For this reason they are often kept as family pets, though they still retain natural horse behavior, including a natural fight or flight instinct, and must be treated like an equine, even if they primarily serve as a companion animal. They are also trained as service animals, akin to assistance dogs for disabled people. Miniature horses are also trained for driving, equine agility, and other competitive horse show type events.Otospondylomegaepiphyseal dysplasia
Otospondylomegaepiphyseal dysplasia (OSMED) is an autosomal recessive disorder of bone growth that results in skeletal abnormalities, severe hearing loss, and distinctive facial features. The name of the condition indicates that it affects hearing (oto-) and the bones of the spine (spondylo-), and enlarges the ends of bones (megaepiphyses).
The features of OSMED are similar to those of another skeletal disorder, Weissenbacher-Zweymüller syndrome. Otospondylomegaepiphyseal dysplasia is a subtype of collagenopathy, types II and XI.Primordial dwarfism
Primordial dwarfism (PD) is a form of dwarfism that results in a smaller body size in all stages of life beginning from before birth. More specifically, primordial dwarfism is a diagnostic category including specific types of profoundly proportionate dwarfism, in which individuals are extremely small for their age, even as a fetus. Most individuals with primordial dwarfism are not diagnosed until they are about 3–5 years of age.
Medical professionals typically diagnose the fetus as being small for gestational age, or as showing intrauterine growth restriction when an ultrasound is conducted. Typically, people with primordial dwarfism are born with very low birth weights. After birth, growth continues at a much slower rate, leaving individuals with primordial dwarfism perpetually years behind their peers in stature and in weight.
Most cases of short stature are caused by skeletal or endocrine disorders. The five subtypes of primordial dwarfism are among the most severe forms of the 200 types of dwarfism, and some sources estimate that there are only 100 individuals in the world with the disorder. Other sources give the number of people currently affected in North America as being as high as 100.There are as yet no effective treatments for primordial dwarfism. It is rare for individuals affected by primordial dwarfism to live past the age of 30. In the case of microcephalic osteodysplastic primordial dwarfism type 2 (MOPDII), there can be increased risk of vascular problems, which may cause premature death.Psychosocial short stature
Psychosocial short stature (PSS) is a growth disorder that is observed between the ages of 2 and 15, caused by extreme emotional deprivation or stress.
The symptoms include decreased growth hormone (GH) and somatomedin secretion, very short stature, weight that is inappropriate for the height, and immature skeletal age. This disease is a progressive one, and as long as the child is left in the stressing environment, his or her cognitive abilities continue to degenerate. Though rare in the population at large, it is common in feral children and in children kept in abusive, confined conditions for extended lengths of time. It can cause the body to completely stop growing but is generally considered to be temporary; regular growth will resume when the source of stress is removed.Robinow syndrome
Robinow syndrome is an extremely rare genetic disorder characterized by short-limbed dwarfism, abnormalities in the head, face, and external genitalia, as well as vertebral segmentation. The disorder was first described in 1969 by human geneticist Meinhard Robinow, along with physicians Frederic N. Silverman and Hugo D. Smith, in the American Journal of Diseases of Children. By 2002, over 100 cases had been documented and introduced into medical literature.Two forms of the disorder exist, dominant and recessive, of which the former is more common. Patients with the dominant version often suffer moderately from the aforementioned symptoms. Recessive cases, on the other hand, are usually more physically marked, and individuals may exhibit more skeletal abnormalities. The recessive form is particularly frequent in Turkey. However, this can likely be explained by a common ancestor, as these patients' families can be traced to a single town in Eastern Turkey. Clusters of the autosomal recessive form have also been documented in Oman and Czechoslovakia.The syndrome is also known as Robinow-Silverman-Smith syndrome, Robinow dwarfism, fetal face, fetal face syndrome, fetal facies syndrome, acral dysostosis with facial and genital abnormalities, or mesomelic dwarfism-small genitalia syndrome. The recessive form was previously known as Covesdem syndrome.Seckel syndrome
Seckel syndrome, or microcephalic primordial dwarfism (also known as bird-headed dwarfism, Harper's syndrome, Virchow–Seckel dwarfism and bird-headed dwarf of Seckel) is an extremely rare congenital nanosomic disorder. Inheritance is autosomal recessive. It is characterized by intrauterine growth retardation and postnatal dwarfism with a small head, narrow bird-like face with a beak-like nose, large eyes with down-slanting palpebral fissures, receding mandible and intellectual disability.
A mouse model has been developed. This mouse model is characterized by a severe deficiency of ATR protein. These mice suffer high levels of replicative stress and DNA damage. Adult Seckel mice display accelerated ageing. These findings are consistent with the DNA damage theory of aging.Silver–Russell syndrome
Silver–Russell syndrome (SRS), also called Silver–Russell dwarfism or Russell–Silver syndrome (RSS) is a growth disorder occurring in approximately 1/50,000 to 1/100,000 births. In the United States it is usually referred to as Russell–Silver syndrome, and Silver–Russell syndrome elsewhere. It is one of 200 types of dwarfism and one of five types of primordial dwarfism.
There is no statistical significance of the syndrome occurring preferentially in either males or females.Thanatophoric dysplasia
Thanatophoric dysplasia (thanatophoric dwarfism) is a severe skeletal disorder characterized by a disproportionately small ribcage, extremely short limbs and folds of extra skin on the arms and legs.