What is dwarfism

Dwarfism is restricted growth condition characterized by short stature. Dwarfism (restricted growth) is commonly described as having a final adult height of 4’10” (125 cm) or less due to a medical condition. Some people prefer the term “short stature” rather than “dwarf” or “dwarfism.” So it’s important to be sensitive to the preference of someone who has this disorder. Short stature disorders do not include familial short stature — short height that’s considered a normal variation with normal bone development.

There are two main types of dwarfism:

• Proportionate dwarfism – a general lack of growth, where the length of the trunk and limbs are in proportion
• Disproportionate dwarfism – where the limbs are shorter or out of proportion with other parts of the body

As well as having short stature, some people with dwarfism also have other physical problems, such as bowed legs or an unusually curved spine.

However, most people don’t have any other serious problems. They can often live a relatively normal life and have a normal life expectancy.

Types of dwarfism

Proportionate dwarfism

Proportionate short stature means there is general lack of growth throughout the body. The length of the trunk (abdomen and chest) remains in normal proportion with the legs.

Pituitary dwarfism (Growth Hormone deficiency, Panhypopituitarism)

Pituitary dwarfism involves abnormally short stature with normal body proportions. Pituitary dwarfism can be categorized as either congenital (present at birth) or acquired.

A study conducted in the US of 80,000 Utah school children, indicated that 555 children were below the third height percentile and had growth rates less than 5 cm/year; of these children, 33 had growth Hormone deficiency, an incidence rate of 1 case per 3,500 children.

Worldwide estimates vary usually dude to lack of reporting and recording but estimates range from 1:30,000 to 1:1800.

Pituitary dwarfism may be associated with deficiencies of other hormones, including the following:

• Thyrotropins (control production of thyroid hormones)
• Vasopressin or ADH (anti-diuretic hormone) controls water balance in the body
• Gonadotropins (control production of male and female sex hormones)
• Adrenocorticotrophic hormone or ACTH (controls the adrenal gland and its production of cortisol, DHEA, and other hormones).

Progression of Pituitary dwarfism (Growth hormone deficiency, Panhypopituitarism)

• A variety of genetic syndromes, a tumor in the pituitary gland, the absence of the pituitary gland, or trauma are some of the known causes of this condition, but in most cases no underlying cause of the deficiency is found. Growth retardation may become evident in infancy and persists throughout childhood. The “growth curve,” demonstrated by plotting sequential height measurements on a standardized growth chart, may range from flat (no growth) to very shallow (minimal growth). Normal puberty may or may not occur, depending on the degree of pituitary insufficiency (inability of the pituitary to produce adequate hormone levels other than growth hormone).

How is Pituitary dwarfism (Growth hormone deficiency, Panhypopituitarism) Diagnosed?

A physical examination including weight, height, and body proportions will show signs of retarded growth rate and deviation from normal growth curves.

Tests include the following:

• A determination of bone age from hand x-ray (extremity X-ray) is often recommended.
• Measurement of growth hormone levels confirms that the disorder is caused by dysfunction of the pituitary gland.
• Other hormone levels should be determined as lack of growth hormone may not be an isolated problem.
• X-ray may show skull abnormalities such as small, enlarged, or empty sella or a space-occupying lesion.
• A CT and/or MRI scan of the head may be ordered.

Prognosis of Pituitary dwarfism (Growth hormone deficiency, Panhypopituitarism)

Growth rates are improved in most children treated with growth hormones, although the effectiveness of treatment may decrease with prolonged treatment.

How is Pituitary dwarfism (Growth hormone deficiency, Panhypopituitarism) Treated?

Replacement therapy with synthetic growth hormone can be used for children with documented growth hormone deficiency. No ideal treatment schedule has yet been determined.

If the deficiency is an isolated growth hormone deficiency, synthetic growth hormone is given alone. If the deficiency is not isolated, other hormone replacement preparations will be required as well.

Morquio Syndrome

Morquio Syndrome is a metabolism disorder where the body can’t break down long chains of sugar molecules called glycosaminoglycans. These build up in the body and brain and damage organs. This is estimated to occur in approximately 1 in every 200,000 births.

Primordial Dwarfism

Primordial Dwarfism – this term covers a number of different conditions (MOPD type I, II & III; Seckel Syndrome, Russell-Silver Syndrome, Meyer-Gorlin Syndrome). Growth is proportionate, but severely delayed. Primordial dwarfism is very rare and there are currently estimated to be a few hundred individuals with this condition worldwide.

In Utero Growth Disorders

In Utero Growth Disorders, including Russell Silver Syndrome – this covers a range of conditions where babies are born much smaller than other newborns. There are many reasons why this may occur, but there is often not an identifiable cause.

Disproportionate short stature

Disproportionate short stature occurs when there is a problem with the way joints and bones grow. Certain limbs may be shorter, or there might be a severe lack of general, all-over body growth. Conditions associated with disproportionate short stature are usually caused by a genetic condition. Many children born with disproportionate short stature will have average-height parents and the genetic condition will have occurred spontaneously. One such condition is Achondroplasia. Most people with restricted growth conditions have normal intelligence and normal life expectancy.

Achondroplasia

Achondroplasia is a rare genetic condition, but one of the most common types of dwarfism with disproportionate short stature. People with the condition have an average sized trunk and short arms and legs. It’s literal meaning of “no cartilage growth” is misleading, but really refers to poor bone growth resulting in shortened limbs. The tissues around the limbs are not affected and continue to grow leading to bulky arms and legs. Growth charts designed specifically for children with Achondroplasia can be used to monitor growth.

Achondroplasia is estimated to occur in approximately 1 in every 26,000 births. About 80 percent of people with achondroplasia are born to parents of average height. A person with achondroplasia and with two average-size parents received one mutated copy of the gene associated with the disorder and one normal copy of the gene. Average size parents of a child with Achondroplasia have very small chance of having another child with the condition. In adults with Achondroplasia the inheritance pattern is autosomal dominant. A person with the disorder may pass along either a mutated or normal copy to his or her own children.

Ultrasound scans may detect disproportionately short limbs at around 25 weeks of pregnancy. For couples where one or both has the condition, a chorionic villus sampling test is available at 12 weeks of pregnancy.

Achondroplasia is due to a change in the gene that codes for Fibroblast Growth Factor Receptor 3 (FGFR3), which results in abnormal cartilage formation. In almost all cases the single base change is exactly the same. The protein made by the FGFR3 gene is a receptor that regulates bone growth by limiting the formation of bone from cartilage (a process called ossification), particularly in the long bones. With achondroplasia, the FGFR3 gene causes the receptor to be overly active, which interferes with ossification and leads to the disturbances in bone growth seen with this disorder.

People with Achondroplasia have a normal intelligence and life expectancy. Most are born to average size parents.

Many practical difficulties can be overcome with a little imagination. There is no reason why someone with Achondroplasia shouldn’t participate in most activities. Scientists believe that people with dwarfism find out their own limits and these aren’t imposed upon them by society.

People with Achondroplasia have a range of characteristics including:

• A near normal trunk length with shorter arms and legs
• A large head with prominent forehead and flattened bridge of the nose
• An increased curvature of the lower spine (lumbar lordosis)
• Bowing of the lower legs
• Possible crowded teeth
• Short, broad feet and hands with separation between middle and ring fingers (the ‘trident’ hand)
• Exceptionally flexible joints
• Babies with Achondroplasia may develop motor skills and mobility more slowly than normal because of the combination of a heavier head and shorter arms and legs, but ultimately development is within the expected normal range.

Some medical complications associated with Achondroplasia are listed below. Note: most of these affect only a minority of people with the condition.

• Glue ear (otitis media with effusion)/ hearing impairment
• Breathing problems in young children
• Hydrocephalus
• Spinal stenosis leading to compression of nerves to the limbs
• Joint problems due to leg bowing

Hypochondroplasia

Hypochondroplasia is a rare inherited skeletal dysplasia (condition of abnormal bone growth or development) causing short stature due to short limbs. Hypochondroplasia affects both males and females. Where the only feature in an individual is short stature, medical intervention may not be sought. As a result, the incidence of hypochondroplasia is uncertain. It is thought that hypochondroplasia incidence could be 1:15,000 to 1:40,000 live births. About 70 per cent of people with hypochondroplasia have an identifiable mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene on chromosome 4p16.3. The remaining 30 per cent will either have a so far unrecognised mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene or a mutation in other as yet unidentified genes.

Features of hypochondroplasia may include:

• Short stature with an adult height in the range of 128 -151 cm (4 feet, 2 inches to 4 feet 11 inches);
• Disproportionate arms and legs with short, broad hands and feet;
• Macrocephaly (an enlarged head);
• Limitation of elbow movement;
• Lordosis (exaggerated curvature at the lower end of the spine);
• Increased joint mobility;
• Learning problems (it has not yet been determined whether this is in fact a feature of hypochondroplasia).

It is not easy to diagnose hypochondroplasia in very young children and may be even be missed in adults. Diagnosis is made by identifying the features known to appear in hypochondroplasia together with radiological (x-ray) findings. DNA based testing can confirm the FGFR3 gene mutation but cannot be used to eliminate the diagnosis.

Hypochondroplasia is not a curable condition and treatment will be symptomatic for specific features. Surgical limb lengthening can be considered but is a drawn out and painful process. Human growth hormone therapy has been given to some children with hypochondroplasia but has shown mixed results. A range of support for families, based on perception of the effect of being of short stature at school and in the wider community, is available. Families can obtain information about aids to ameliorate difficulties in access and operation of equipment from local and national statutory and support organizations.

Hypochondroplasia is an autosomal dominant condition. Chorionic Villus sampling or amniocentesis is available if a parent has hypochondroplasia and a mutation in the FGFR3 gene has been identified. Where the mutation has not been identified ultrasound scanning is the only method of prenatal testing. Families where hypochondroplasia has been diagnosed should seek genetic counselling.

Diastrophic Dysplasia

Diastrophic Dysplasia is a rare, inherited skeletal dysplasia (a condition of abnormal bone growth or development) affecting both females and males equally. It was first described in 1960 by French doctors, Dr M. Lamy and Dr P. Maroteaux, as Le nanisme diastrophique.

Diastrophic Dysplasia is a disorder of restricted growth, spinal curvature and abnormalities of the fingers and toes. Intelligence is normal. The average height of adults is 118 cm (males: 86-127 cm; females 104-122 cm). Respiratory complications can cause an increase in infant mortality, but individuals who survive infancy have a normal life span.

The incidence is thought to be 1 in 110,000 births and it is caused by mutations in the SLC26A2 (Diastrophic DysplasiaST) gene on chromosome 5q31-q34.

The ways and severity that individuals with Diastrophic Dysplasia are affected vary.

The features of Diastrophic Dysplasia include:

• shortening of the limbs but with a normal sized skull;
• small chest;
• protuberant abdomen;
• cleft palate in about 33% of cases
• swelling of the ears giving a ‘cauliflower’ appearance;
• joint contractures;
• shortening of the bones of the hands including hitchhiker thumbs (short bones cause the thumb to take up the typical hitchhiker position);
• club feet, varying from mild to severe due to bone abnormalities;
• progressive Scoliosis (sideways curvature of the spine), lumbar lordosis (forward curvature of the lower spine) and cervical kyphosis (outward curvature of the upper spine).

Diastrophic Dysplasia is diagnosed by recognition of the clinical features of the disorder, radiographic (x-ray) findings and in some cases by molecular genetic testing of the SLC26A2 gene.

Diastrophic Dysplasia is not a curable condition and treatment will be symptomatic for specific features. It important to maintain joint positioning and mobility as much as possible using physiotherapy and surgical correction for club feet to allow walking. This is often extremely difficult and ideally should be performed by a surgeon with experience of other children with diastrophic dysplasia.This is true of any surgical intervention in children with diastrophic dysplasia. Monitoring of abnormalities of the bones of the limbs and particularly of the spine is important since surgical intervention may be necessary. Progressive abnormality of the bones of the spine in the neck is an important complication and should be looked for specifically. This may also require surgical treatment. Surgical intervention to release joint contracture is not usually recommended since these tend to recur.

A range of support for families, based on the practical and psychological effects of being of short stature at school and in the wider community, is available. Families can obtain information about aids to ameliorate difficulties in access and operation of equipment from local and national statutory and support organisations.

Diastrophic Dysplasia is inherited in autosomal recessive manner. A range of testing is available. Where Diastrophic Dysplasia is known in a family and the mutations in the SLC26A2 gene in the affected individual are known, chorionic villus sampling can be used at about 10-12 weeks or amniocentesis at about 15-18 weeks. Ultrasound examination may identify typical skeletal abnormalities.

Pseudoachondroplasia

Pseudoachondroplasia is another form of short-limb dwarfism / restricted growth. Often, the diagnosis is not made at birth, but when the child is 2-3 years of age. At first, growth is normal. At 2-3 years of age, the diagnosis is suspected because of a delay in walking or an unusual, waddling gait is noted. As the growth rate slows, the trunk appears long with lumbar lordosis and rhizomelic shortening of the limbs. Final adult height is 80-130cm. A height curve is available for individuals with pseudoachondroplasia. It may be helpful for a child’s paediatrician to have a copy of this height chart.

Individuals with pseudoachondroplasia have normal head size and facial features. A characteristic waddling gait is seen due to hip involvement. Legs are malaligned with a variety of knee deformities noted, including bow-legs (genu varum), knock-knees (genu valgum), and windswept deformities (bow-leg on one side and knock-knee on the other side). Joint hypermobility is seen, especially at the wrists and fingers; however, elbow extension is often limited. Hands and feet are short. Osteoarthritis occurs in early adulthood, especially in the weight-bearing joints. The most important complications of pseudoachondroplasia are orthopedic in nature. Correction of the hip and knees are done in most individuals.

Pseudoachondroplasia is inherited in an autosomal dominant manner. This means that a person with pseudoachondroplasia and their average-sized partner have a 50% or 1 in 2 chance of having children with pseudoachondroplasia. Like many other autosomal dominant conditions, children with pseudoachondroplasia are often born to average-sized parents. In these cases, pseudoachondroplasia is due to a new mutation or genetic change. The gene for pseudoachondroplasia has been discovered. It is called cartilage oligomeric protein or COMP for short.

Spondylo-epiphyseal Dysplasia Congenita

Spondylo-epiphyseal Dysplasia Congenita (SEDC or SED) describes several bone disorders characterized by progressive abnormalities of the “spondylo” or spine and the “epiphyses” (growing ends of the long or short tubular-shaped bones), with sparing of the other components of skeleton. It results in stunting of growth and premature degenerative arthropathy due to incongruity of joint surfaces. The underlying defect lies in type II collagen.

It has two varieties:

• SED congenita – presenting at birth with predominant involvement of knees and hips, short neck and vertebral abnormalities at the base of skull
• SED tarda – where the main abnormality is in the spine, which becomes shortened and stiff. There is often mild curvature of spine and hands may reach down to knees.

This occurs in approximately 1 in every 100,000 births and is one of the commoner forms of dwarfism.

Ellis – van Creveld Syndrome

Ellis – van Creveld Syndrome – people with this condition have particularly short forearms and lower legs and a narrow chest with short ribs. Changes in the EVC and EVC2 genes cause Ellis-van Creveld syndrome. Researchers have not determined the functions of these genes, but they have identified mutations in both genes that can cause Ellis-van Creveld syndrome. This occurs in approximately 1 in every 60,000 – 200,000 births, though is much more common in certain populations.

Metatropic Dysplasia / Kniest Dysplasia

Metatropic Dysplasia / Kniest Dysplasia – people with Kniest dysplasia are born with a short trunk and shortened arms and legs. Kniest dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. Type II collagen is essential for the normal development of bones and other connective tissues that form the body’s supportive framework. Most changes in the COL2A1 gene that cause Kniest dysplasia interfere with the assembly of type II collagen molecules. Abnormal collagen prevents bones and other connective tissues from developing properly, which leads to the signs and symptoms of Kniest dysplasia. This a rare condition and the exact incidence is unknown.

Conradi-Hunermann syndrome

Conradi-Hunermann syndrome describes at least two different conditions. These conditions are part of the group which together are called chondrodysplasia punctata. This describes an unusual pattern which can be seen in the X-rays of babies and young children where the ends of the bones appear ‘stippled’ or ‘punctate’.

In Conradi-Hunermann syndrome this pattern is present and the bones of the arms and legs are short causing short stature. The bones of the face may also be involved. Some children with this condition have eye changes including cataracts. Babies may be born with a skin rash and can later develop thickening of the skin. The hair may be sparse or absent in patches.

It can be difficult to differentiate the various forms of this condition.

There is an autosomal dominant and X-linked dominant form of Conradi-Hunermann syndrome. In addition there are autosomal recessive and X-linked recessive forms of chondrodysplasia punctata which can be sometimes be mistaken for Conradi-Hunermann syndrome. The genes which cause some of these conditions are known and can be tested for.

Prenatal diagnosis may be possible if the exact cause of the condition is known. In other cases ultrasound scanning may be helpful.

Dwarfism complications

Complications of dwarfism-related disorders can vary greatly, but some complications are common to a number of conditions.

Disproportionate dwarfism

The characteristic features of the skull, spine and limbs shared by most forms of disproportionate dwarfism result in some common problems:

• Delays in motor skills development, such as sitting up, crawling and walking
• Frequent ear infections and risk of hearing loss
• Bowing of the legs
• Difficulty breathing during sleep (sleep apnea)
• Pressure on the spinal cord at the base of the skull
• Excess fluid around the brain (hydrocephalus)
• Crowded teeth
• Progressive severe hunching or swaying of the back with back pain or problems breathing
• Narrowing of the channel in the lower spine (spinal stenosis), resulting in pressure on the spinal cord and subsequent pain or numbness in the legs
• Arthritis
• Weight gain that can further complicate problems with joints and the spine and place pressure on nerves

Proportionate dwarfism

With proportionate dwarfism, problems in growth and development often result in complications with poorly developed organs. For example, heart problems often present in Turner syndrome can have a significant effect on health. An absence of sexual maturation associated with growth hormone deficiency or Turner syndrome affects both physical development and social functioning.

Pregnancy

Women with disproportionate dwarfism may develop respiratory problems during pregnancy. A C-section (cesarean delivery) is almost always necessary because the size and shape of the pelvis doesn’t allow for successful vaginal delivery.

Public perceptions

Most people with dwarfism prefer not to be labeled by a condition. However, some people may refer to themselves as dwarfs or little people. The word “midget” is generally considered an offensive term.

People of average height may have misconceptions about people with dwarfism. And the portrayal of people with dwarfism in modern movies often includes stereotypes. Misconceptions can impact a person’s self-esteem and limit opportunities for success in school or employment.

Children with dwarfism are particularly vulnerable to teasing and ridicule from classmates. Because dwarfism is relatively uncommon, children may feel isolated from their peers.

Dwarfism causes

Dwarfism (restricted growth) may be caused by many different medical conditions, and is more noticeable in some conditions than others.

Most dwarfism-related conditions are genetic disorders, but the causes of some disorders are unknown. Most occurrences of dwarfism result from a random genetic mutation in either the father’s sperm or the mother’s egg rather than from either parent’s complete genetic makeup.

What causes dwarfism

The most common cause of proportionate short stature is being born to small parents, but it can sometimes occur as a result of the body not producing enough growth hormone. The cause of growth hormone deficiency can sometimes be traced to a genetic mutation or injury, but for most people with the disorder, no cause can be identified.

Certain genetic syndromes, such as Turner syndrome and Prader-Willi syndrome, can also cause proportionate short stature.

Turner syndrome, a condition that affects only girls and women, results when a sex chromosome (the X chromosome) is missing or partially missing. A female inherits an X chromosome from each parent. A girl with Turner syndrome has only one fully functioning copy of the female sex chromosome rather than two.

Disproportionate short stature usually occurs as part of a genetic condition, such as achondroplasia. Many children born with disproportionate short stature have parents of average height and the faulty gene causing the condition occurred by chance.

If your child is diagnosed with dwarfism, tests will be carried out to try to identify the underlying cause.

Causes of Proportionate Short Stature

The main cause of proportionate short stature (proportionate short stature) is being born to small parents.

A less common cause is the body not producing enough growth hormone, which is estimated to affect one in every 3,500 to 4,000 children.

This may be present at birth, because of problems with the pituitary gland (a pea-sized gland below the brain responsible for producing several important hormones) or as part of another condition. It can also start in childhood, as the result of an injury, a brain tumor or radiotherapy to the brain.

In about half of children with growth hormone deficiency, the cause is unknown.

Other possible causes of proportionate short stature include:

• long-term conditions – such as those affecting the lungs, heart or kidneys
• steroid treatment for a chronic condition – such as asthma
• genetic abnormalities – such as Down’s syndrome, Noonan syndrome, Turner syndrome, Prader-Willi syndrome and short stature homeobox-containing gene (SHOX) deficiency
• malnutrition or poor absorption of food – for example, in Celiac disease

If your child is diagnosed with restricted growth, tests may be carried out to try to identify the underlying cause.

Causes of Disproportionate Short Stature

Conditions associated with disproportionate short stature are usually caused by a faulty gene. The affected genes stop the bones and cartilage developing properly, leading to restricted growth that is often noticeable from birth.

Many children born with disproportionate short stature have parents of average height and the change to the gene happens by chance. However, people with conditions that cause disproportionate short stature may pass their condition on to their children.

The most common cause of disproportionate short stature is a condition called achondroplasia, which is estimated to affect around one in every 25,000 people.

Other conditions that cause disproportionate short stature include:

• hypochondroplasia
• mucopolysaccharide disease
• diastrophic dysplasia
• spondyloepiphyseal dysplasia
• multiple epiphyseal dysplasia
• pseudoachondroplasia
• Conradi syndrome
• Ellis-van Creveld syndrome.

Dwarfism symptoms

People with dwarfism (restricted growth) often have no symptoms other than short stature, although some people have associated health problems.

Symptoms commonly seen in people with proportionate and disproportionate short stature are outlined below.

Proportionate dwarfism

People with proportionate short stature grow very slowly and have a general lack of growth throughout the body. The length of the trunk (tummy and chest) remains in normal proportion with the legs.

Proportionate dwarfism may not be noticeable until later in childhood or until a child reaches puberty.

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.

Additional symptoms associated with proportionate short stature depend on the underlying cause. For example:

• people with growth hormone deficiency may have low energy levels, increased body fat, weak bones (osteoporosis), dry skin, reduced muscle strength and high cholesterol
• girls and women with Turner syndrome won’t start having periods and won’t be able to have children
• people with Prader-Willi syndrome may have a constant desire to eat, reduced muscle tone (hypotonia), learning difficulties and behavioural problems
• people with chronic illnesses affecting organs such as lungs, heart or kidneys will have further symptoms relating to their underlying condition

Disproportionate dwarfism

Most people with dwarfism have disorders that cause disproportionately short stature. In people with disproportionate short stature, there is an overall lack of growth, and certain limbs may be shorter or out of proportion with other parts of the body. 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.

People with achondroplasia, one of the most common causes of disproportionate short stature, typically have:

• a normal-length trunk with short arms and legs, with particularly short upper arms and upper legs
• a large head with a prominent forehead and a flattened bridge of the nose
• short and wide hands and feet
• short fingers and toes, often with a wide separation between the middle and ring fingers
• limited mobility at the elbows
• an adult height around 4 feet (122 cm)

Most people with disproportionate short stature don’t have any other significant health problems, although some people with achondroplasia have:

• bowed legs, which may cause ankle or knee pain
• abnormal curvature in the top of the spine (kyphosis) and/or sideways curvature of the spine (scoliosis)
• a build-up of fluid around the brain (hydrocephalus)
• repeated middle ear infections, which can cause hearing difficulties
• irregular breathing at night (sleep apnea), which can interrupt sleep and cause excessive sleepiness during the day
• numbness and weakness in the legs, caused by the compression of the spinal cord and nerves leaving the spine.

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)

Dwarfism diagnosis

A diagnosis of restricted growth (dwarfism) is based on symptoms, height measurements, family history and tests.

Depending on the cause of the condition, restricted growth may be diagnosed before or soon after a child is born, or when growth problems become more obvious as they get older.

Tests may not need to be carried out if you or your child don’t have any other health problems.

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.

Diagnosing growth hormone deficiency

Growth hormone deficiency is usually diagnosed using growth hormone stimulation tests.

Medicine is injected into a vein to cause growth hormone levels in the blood to increase. If the level of growth hormone is found to be lower than normal, it indicates growth hormone deficiency.

A scan of the brain is necessary to look at the pituitary gland (which produces growth hormone) if blood tests show low levels of growth hormone.

Diagnosing conditions that cause restricted growth

The following tests can be used to diagnose a condition that causes short stature:

• blood tests to check for any liver, kidney and bone problems or malnutrition – blood tests can also be used to analyse chromosomes, which can help to diagnose some genetic conditions, such as Turner syndrome
• urine tests to confirm some enzyme deficiency disorders – such as mucopolysaccharide disease
• imaging tests such as X-rays or MRI scans to check for abnormalities in the bones or pituitary gland – which may indicate growth hormone deficiency

Diagnosis in pregnancy

Diagnosis during pregnancy (also called prenatal diagnosis) may be offered to parents who have a genetic history of a condition that causes short stature.

Some potential abnormalities may be visible during routine ultrasound scans, but tests such as chorionic villus sampling or amniocentesis are needed to confirm a diagnosis, as they can be used to see if your baby carries one of the faulty genes associated with restricted growth.

Dwarfism treatment

Treatments recommended for people with restricted growth depend on the cause of the condition and any associated problems they have. A number of different healthcare professionals will usually be involved in your care.

This team may evolve as your child’s needs change, and your family doctor or pediatrician can coordinate the care.

Specialists in your care team may include:

• Hormone disorder specialist (endocrinologist)
• Ear, nose and throat (ENT) specialist
• Specialist in skeletal disorders (orthopedist)
• Specialist in genetic disorders (medical geneticist)
• Heart specialist (cardiologist)
• Eye specialist (ophthalmologist)
• Mental health provider, such as a psychologist or psychiatrist
• Nervous system abnormalities specialist (neurologist)
• Dental specialist in correcting problems with teeth alignment (orthodontist)
• Developmental therapist, who specializes in therapy to help your child develop age-appropriate behaviors, social skills and interpersonal skills
• Occupational therapist, who specializes in therapy to develop everyday skills and to use adaptive products that help with everyday activities

Some people with restricted growth may be able to have treatment to help them grow more than they otherwise would, although not everyone will need treatment.

Some people with restricted growth may benefit from treatment with growth hormone injections, which can help a child with restricted growth grow more than they otherwise would.

In cases of disproportionate short stature where the legs are particularly short, a leg-lengthening procedure is sometimes used, although this is controversial and there is uncertainty about its safety and effectiveness.

Support and treatment is also available to help with related problems, such as associated health conditions and difficulties with daily activities.

Growth hormone medication

The National Institute for Health and Care Excellence ¹ recommends human growth hormone treatment (somatropin) as an option for children whose poor growth is associated with:

• Growth hormone deficiency
• Turner syndrome
• Prader-Willi syndrome
• Chronic kidney disease
• A particular genetic fault – known as short stature homeobox-containing gene (SHOX) deficiency

NICE ¹ also recommends the treatment for children who are born small and fail to catch up in growth by the age of four or later.

Somatropin treatment should be started and monitored by a child health specialist (pediatric endocrinologist) with expertise in managing growth hormone disorders in children. It’s given as a single daily injection, which can usually be done by a parent or carer.

Skin reactions are the most commonly reported side effect of somatropin. In very rare cases, the treatment is associated with persistent severe headaches, vomiting and vision problems.

Children with growth hormone deficiency respond very well to growth hormone treatment and may be able to reach a relatively normal adult height. The effectiveness in children with other conditions can vary.

Growth hormone treatment may stop once your child stops growing, but in some cases it may be given into adulthood because it can sometimes help prevent problems such as weak bones (osteoporosis).

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.

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

Leg-lengthening surgery

If a person has particularly short legs, a leg-lengthening process, known as distraction, may be an option. This involves dividing the leg bone and fixing it to a special frame. This is gradually adjusted every day to encourage the bone to grow over time.

This can sometimes result in a significant increase in height, but it’s a lengthy treatment and has a risk of complications, so it’s not always recommended.

The National Institute for Health and Care Excellence ² says there is uncertainty about the safety and effectiveness of this procedure, so they recommend making sure you understand exactly what it involves and to talk to your surgeon or doctor about the risks if it’s suggested as a treatment.

Some people have pain after the limb-lengthening procedure. Other possible complications include:

• poor bone formation
• infection
• bone lengthening at an inappropriate rate
• blood clots

Support and treatment for related problems

As restricted growth can be associated with several related conditions and problems, affected children and adults are likely to be cared for by a team of different healthcare professionals.

These may include:

• a pediatrician (child health specialist)
• a nurse specialists
• a physiotherapist
• an occupational therapist
• a dietician
• an audiologist (hearing specialists)
• a speech and language therapist
• a neurologist (specialist in nervous system disorders)
• an orthopedic surgeon
• a geneticist

You may have regular check-ups with members of your care team, so your health can be monitored and any problems that develop can be treated.

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.

Lifestyle and home remedies

Talk with your pediatrician or a specialist about at-home care. Issues particularly critical for children with disproportionate dwarfism include:

• Car seats. Use an infant car seat with firm back and neck supports. Continue using a car seat in the rear-facing direction to the highest weight and height possible (and beyond the recommended age limit).
• Infant carriers and play equipment. Avoid infant devices — such as swings, umbrella strollers, carrying slings, jumper seats and backpack carriers — that don’t support the neck or that curve the back into a C shape.
• Adequate support. Support your child’s head and neck when he or she is seated.
• Complications. Monitor your child for signs of complications, such as ear infection or sleep apnea.
• Posture. Promote good posture by providing a pillow for the lower back and a footstool when your child is sitting.
• Healthy diet. Begin healthy eating habits early to avoid later problems with weight gain.
• Healthy activities. Encourage participation in appropriate recreational activities, such as swimming or bicycling, but avoid sports that involve collision or impact, such as football, diving or gymnastics.

Coping and support

If your child has dwarfism, you can take a number of steps to help him or her cope with challenges and function independently:

• Seek help. The nonprofit organization Little People of America provides social support, information about disorders, advocacy opportunities and resources. Many people with dwarfism stay actively involved in this organization throughout their lives.

• Modify your home. Make changes to your home, such as putting specially designed extensions on light switches, installing lower handrails in stairways and replacing doorknobs with levers. The Little People of America website ³ provides links to companies that sell adaptive products, such as size-appropriate furniture and everyday household tools.
• Provide personal adaptive tools. Everyday activities and self-care can be a problem with limited arm reach and problems with dexterity. The Little People of America website ³ provides links to companies that sell adaptive personal products and clothing. An occupational therapist also may be able to recommend appropriate tools for home and school use.
• Talk to educators. Talk to school personnel about what dwarfism is, how it affects your child, what needs your child may have in the classroom and how the school can help meet those needs.
• Talk about teasing. Encourage your child to talk to you about his or her feelings, and practice responses to insensitive questions and teasing. If your child tells you that bullying occurs in school, seek help from your child’s teacher, principal or the school guidance counselor and ask for a copy of the school’s policy on bullying.

1. Human growth hormone (somatropin) for the treatment of growth failure in children. https://www.nice.org.uk/guidance/TA188[↩][↩]
2. Intramedullary distraction for lower limb lengthening. https://www.nice.org.uk/guidance/ipg197[↩]
3. Little People of America. http://www.lpaonline.org/[↩][↩]