What is short stature?

Height, or 'stature', is determined by a complex interaction between a person's genes, environment, nutrition, development before birth and during early life, and other factors. A classification of 'short stature' is given to children whose height is two standard deviations below the average height for other children of the same age, sex and family background. Of all people, 2.3% fit into this category [1] .

Short stature in itself is not a medical problem; most people in this category are simply naturally short and lead normal, healthy lives. Many children are 'late bloomers' - at one stage shorter than expected, but then 'catch up' as they mature. However, in some children, short stature can indicate an underlying medical problem.

Synthetic human growth hormone, also known as somatropin, can be used to treat short stature, but its benefits and costs should be considered on an individual basis.

 

Human growth hormone

A chemical that stimulates the growth of cells. Also known as somatotropin.

1. Causes of short stature. Accessed 30 June 2015, from

External link

Types

Short stature can be the result of many factors. The most common cause is simply coming from a family background of short height, and/or drawing the 'short stick' in the genetic 'luck of the draw'. However, in some cases short stature can also be the result of an underlying medical condition.

Normal short stature

In most cases, short stature is due to either family genetics or a natural delay of growth and puberty, also known as constitutional short stature. These are also known as types of 'idiopathic' short stature, meaning that there is no specific medical condition responsible for below-average height.

Familial short stature

A child's potential height falls in a range that is largely determined by their genes; shorter parents will likely produce shorter children. A child's final height can vary within this range (for example, this writer has a younger brother who is 10cm taller) and some healthy children of shorter parents will be at the short end of the range.

Constitutional short stature ('late bloomer')

Children develop at different rates. Some children are 'small for their age' and will arrive at developmental milestones later than others. In these cases, the child will have attained their final height later than his or her peers, but is otherwise normal.

Systemic disorders

Short stature can be the result of a large number of different medical disorders [2] [3] [4] :

Genetic disorders

Numerous genetic disorders have short stature as one of their characteristics. These can include (but are not limited to):

Hormone disorders

Hormones regulate growth in the human body. An imbalance in hormone makeup can have many causes, including genetic causes, infections, trauma, and tumours. Some hormone problems can contribute to short stature.

 Conditions that can limit growth include:

Development disorders and environmental conditions

Various problems during pregnancy and infancy can contribute to short stature. These can include:

In addition, various chronic diseases (some of them congenital) can take their toll on a child's body and can contribute towards short stature. These can include:

Congenital

Present from birth.

Corticosteroid

A medication that resembles the cortisol hormone produced in the brain. It is used as an anti-inflammatory medication.

Creutzfeldt-Jakob disease

A rare and fatal degenerative disease that affects the brain. It is caused by an infectious agent and related to bovine spongiform encephalopathy, also known as 'mad cow disease'.

Genetic

Related to genes, the body's units of inheritance or origin.

Growth hormone deficiency

A condition in children in which the pituitary gland does not produce enough growth hormone. This can affect a child’s growth.

Idiopathic

Without a known cause.

Infections

Entry into the body of microorganisms that can reproduce and cause disease.

Malnutrition

A condition in which a person does not receive the right amount of nutrients such as vitamins, minerals and proteins.

Prader-Willi syndrome

A rare genetic disorder that affects development and growth, typically causing poor muscle tone, short stature, incomplete sexual development, cognitive disabilities, problem behaviours and obsessive eating.

Rickets

A bone disease caused by a lack of vitamin D in childhood.

Sickle-cell anaemia

A hereditary form of anaemia in which a defective form of haemoglobin cause red blood cells to be an abnormal crescent shape. This causes the cells to break down prematurely, which can then lead to anaemia.

Trauma

1. Physical injury to the body caused by force or a toxic substance. 2. Psychological damage caused by a severely disturbing experience.

Tumours

A growth caused by an abnormal and uncontrolled reproduction of cells.

Uterus

The hollow organ of the female reproductive system that is responsible for the development of the embryo and fetus during pregnancy. Also known as the womb.

Cushing's syndrome

A group of disorders characterised by high levels of cortisol, an important chemical in the body with numerous functions including stress responses, maintaining blood sugar levels and helping the immune system.

Turner's syndrome

An inherited condition that affects only women, which is caused by the absence of an X chromosome (or part of it). It leads to developmental abnormalities and infertility.

Thalassemia

A hereditary disease caused by faulty production of proteins in red blood cells, leading to their premature destruction and, subsequently, anaemia.

Achondroplasia

An inherited condition in which the growth of the bones is suppressed, resulting in short limbs, and in unusual cases, an extra large skull.

Osteogenesis imperfecta

An inherited condition characterised by extremely brittle bones that fracture easily.

Dwarfism

Underdevelopment of the body that results in short height.

Noonan syndrome

An inherited condition that causes heart disease that is present from birth, short stature and delayed development.

Kabuki syndrome

A rare inherited condition that causes delayed development and intellectual impairment in children. It is physically characterised by arched eyebrows and a flat tip of the nose.

Williams syndrome

A genetic condition characterised by problems including heart disease, developmental delays and learning disabilities, often alongside advanced verbal abilities, overly social personalities and an affinity for music. Physical traits include a long upper lip, small chin, full lips, chubby face and an upturned nose.

2. Lee, M.M. (2006). Idiopathic short stature. New England Journal of Medicine 354:2576–2582.

3. Deodati, A. and Cianfarani, S. (2011). Impact of growth hormone therapy on adult height of children with idiopathic short stature: systematic review. BMJ 342:c7157–c7157.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

Methods for diagnosis

In order to assess your child's status, your doctor will [2] :

  • Measure your child's height against standard growth and development curves;
  • Evaluate your child's height based on their age, health status, and family and developmental history;
  • Examine your child for physical proportions (weight, sitting height) and outward signs of genetic conditions, and;
  • Evaluate your child's bone age from an X-ray image of their hand and wrist.

Your doctor may also want to perform specific tests, including blood tests and growth hormone stimulation, to correctly diagnose the cause of your child's short stature.

Although you may be concerned with your child's present height, it is the pattern of growth that is the most important indicator of health and future height. Thus, your doctor will be interested in how your child has been growing over a period of months and years.

Mid-parental height

In general, expected final height of a child is estimated as the 'mid-parental height', which is the average height of both parents, adjusted for gender.

Mid-parental height is calculated as follows:

For girls - father's height plus mother's height minus 13cm, then divided by two. The range is 8.5cm on either side of this figure.

For boys - father's height plus mother's height plus 13cm, then divided by two. The range is 10cm on either side of this figure.

Thus, for a 170cm father and a 150cm mother, their daughters are expected to be within a 145-162cm range, and their sons within a 155.5-175.5cm range.

The further away a child is from their expected height, the higher the suspicion that there might be an underlying medical problem [5] .

Blood tests

During a blood test, blood can be drawn using a needle or by a finger prick. Your blood can then be analysed to help diagnose and monitor a wide range of health conditions.

Bone age

The measure of maturity of a person's bones.

Genetic

Related to genes, the body's units of inheritance or origin.

Growth hormone stimulation

A test that measures the body's ability to produce growth hormone in response to specific medications.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

2. Lee, M.M. (2006). Idiopathic short stature. New England Journal of Medicine 354:2576–2582.

5. Cheetham, T. and Davies, J.H. (2014). Investigation and management of short stature. Archives of Disease in Childhood 99:767–771.

Types of treatment

Short stature is not a disease and does not necessarily require treatment. Whether or not a person with short stature needs treatment depends on their individual circumstances.

Many parents are concerned that their children's height will affect their social lives and their psychological wellbeing. In some cases that could be true, but studies show that this is not always the case.

Human growth hormone treatment

Human growth hormone (HGH), known in Australia as somatropin, is currently a much-discussed substance for various uses, including 'anti-ageing' treatments and improving muscle mass, bone density and reducing body fat [4] .

For many - though not all - cases of short stature in children, treatment with HGH can help to some extent. For idiopathic short stature, a long-term treatment course that takes 4-7 years can contribute between 3-7cm to a person's final height [2] [3] .

For children whose short stature is caused by growth hormone deficiency, HGH treatment is much more effective, and can add up to 30cm to the child's final height [4] .

HGH can also be used in some cases of short stature caused by genetic syndromes [4] , but will not help at all in others (such as achondroplasia). Generally speaking, in cases where HGH can be effective, it is more effective the earlier treatment starts.

In the past, HGH was extracted from human cadavers and was therefore in very limited supply. In addition, HGH from human sources was a potential source of contamination and disease transfer [6] .

In recent decades, recombinant DNA technology has enabled the production of HGH in large amounts. In 2003, HGH was approved in the United States for use in children with idiopathic short stature, and is also available in Australia for this purpose. However, HGH treatment is still expensive.

Genetic

Related to genes, the body's units of inheritance or origin.

Growth hormone deficiency

A condition in children in which the pituitary gland does not produce enough growth hormone. This can affect a child’s growth.

Idiopathic

Without a known cause.

Recombinant DNA

An artificially-produced form of DNA achieved by joining fragments of DNA molecules obtained from different organisms.

Achondroplasia

An inherited condition in which the growth of the bones is suppressed, resulting in short limbs, and in unusual cases, an extra large skull.

Human growth hormone

A chemical that stimulates the growth of cells. Also known as somatotropin.

Cadavers

A dead body used for anatomical dissection.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

2. Lee, M.M. (2006). Idiopathic short stature. New England Journal of Medicine 354:2576–2582.

3. Deodati, A. and Cianfarani, S. (2011). Impact of growth hormone therapy on adult height of children with idiopathic short stature: systematic review. BMJ 342:c7157–c7157.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

6. Billette de Villemeur, T., Deslys, J.P., Pradel, A., et al. (1996). Creutzfeldt-Jakob disease from contaminated growth hormone extracts in France. Neurology 47:690–695.

Prevention

There is nothing that can outright prevent short stature. Some forms of short stature are affected by conditions during pregnancy and by the child's own environmental factors, especially nutrition and health. Therefore, the best thing you can do is to provide your child with a safe, stress-free and healthy environment during pregnancy and early development, where possible.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

2. Lee, M.M. (2006). Idiopathic short stature. New England Journal of Medicine 354:2576–2582.

3. Deodati, A. and Cianfarani, S. (2011). Impact of growth hormone therapy on adult height of children with idiopathic short stature: systematic review. BMJ 342:c7157–c7157.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

4. Dattani, M. and Preece, M. (2004). Growth hormone deficiency and related disorders: insights into causation, diagnosis, and treatment. The Lancet 363:1977–1987.

6. Billette de Villemeur, T., Deslys, J.P., Pradel, A., et al. (1996). Creutzfeldt-Jakob disease from contaminated growth hormone extracts in France. Neurology 47:690–695.