short stature

Short stature: description

It is estimated that there are about 100,000 short people in Germany. The term “stunted growth” is rather rejected by those affected because it adheres to a discriminatory undertone. That’s why he disappears more and more from the language.

When is one short stature?

In medicine, the term “small” refers to those who remain below the third percentile with their height. Put simply, if 97 percent of peers are taller than you are, you’re considered short-lived. After completion of the longitudinal growth, the limits for men in this country are 1.50 meters and for women at 1.40 meters. Ultimately, however, these numbers are relative, since the average size can vary depending on the population.

Dwarfism is often a temporary phenomenon. Some babies and toddlers are temporarily considered to be short-lived; but some catch up and are normal in adulthood.

How does normal growth work?

From the moment of conception man grows – first in the mother’s womb and after birth until the end of the growth phase. For girls, this usually ends around the age of 16, for boys around the age of 19. Although it can still take some years to grow, but then usually only slightly.

Most people grow in the first years of life (about 25 centimeters in the first year, eleven centimeters in the second and eight centimeters in the third year) and during puberty (about seven to ten centimeters per year).

For the size of a human, the length of the legs is crucial. In the growth joint (epiphysis) of the long bones, new bone substance is constantly being grown during the growth phase – the bones are lengthened.

The growth of the body is largely controlled by hormones, which in turn stimulate cells of different tissues to multiply or enlarge. The most important growth hormone is the so-called somatotropin, also called growth hormone (GH). It is produced in the pituitary gland and released from there into the bloodstream. Through certain receptors in the liver somatotropin leads to the release of IGF (insulin-like growth factors) – a hormone that causes the actual growth of various body tissues such as muscles or bones.

Expected final size

How tall a person becomes is largely genetically determined, but also depends on external factors such as nutrition, possible illnesses and parental care. The expected final size of a person can roughly be calculated on the basis of a rule of thumb. For this, first the mean value is determined from the sizes of the parents. For girls, 6.5 centimeters are deducted from this value, with boys one counts 6.5 centimeters.

Even more reliable is the measurement of bone maturity by means of an X-ray of the left hand, which allows relatively accurate conclusions about the final size.

What forms of dwarfism exist?

There are countless forms of dwarfism. Depending on the point of view, these can be classified into different categories. For example, dwarfism may be primary or secondary. A primary dwarfism is when it occurs on its own. If, on the other hand, it is only the direct or indirect consequence of another underlying disease, then it is a secondary form.

Small dwarfism can also be divided into a native and an acquired form.

Also, one can distinguish whether a proportioned or dysproportionierte dwarfism is present: proportioned dwarfism all body parts are equally affected by the reduced growth, dysproportionierten against only individual parts: For example, only arms and legs can be shortened, the trunk but normal size, such as this is the case with achondroplasia, for example.

Dwarfism: symptoms

It is not possible to make general statements about symptoms of dwarfism, except, of course, that stunted people have a reduced body length. Everything else depends on the nature of the dwarfism. It must, however, be distinguished whether occurring symptoms are actually consequences of dwarfism or just other signs of a common cause.

For example, in some syndromal disorders, dwarfism is only one symptom of many, but all of them are the result of a genetic error. In the case of achondroplasia, on the other hand, dwarfism itself leads to further symptoms such as premature joint wear and back pain.

Dwarfism: causes and risk factors

There are hundreds of causes that can cause dwarfism. They can be divided into larger groups, of which the most important are briefly presented here:

Idiopathic short stature

“Idiopathic” means in medicine that a disease occurs independently and you do not know their exact cause. So there are people who are by definition small-minded, but for whom none of the known triggers can be found. This group also includes the familial dwarfism, so a dwarfism, which occurs frequently in a family. The short-lived or has then also small-sized parents. Familial dwarfism is the most common form of dwarfism rather than disease.

Intrauterine dwarfism

When a child is already small in size, the growth of the fetus has already been delayed in the uterus. One speaks then of intrauterine dwarfism (uterus = uterus). There may be various causes for this, such as the mother smoked during pregnancy, drinking alcohol or taking certain medications. A disturbed function of the mother cake can also result in intrauterine dwarfism. In most cases, the affected children recover the growth arrears within the first two years of life.

Chromosomal disorders and syndromal disorders

DNA, the genetic material of humans, is organized into a total of 46 chromosomes. Certain disorders that result in a change in the number of chromosomes or a defect in the genome, among other things, can lead to small dwarfism. This is the case, for example, with Down syndrome (trisomy 21), in which chromosome 21 is present three times instead of twice. The Noon syndrome, Prader-Willi syndrome, Silver Russell syndrome and DiGeorge syndrome also cause short stature.

skeletal dysplasias

In skeletal dysplasias there is a disturbed bone growth. The most common skeletal dysplasias are achondroplasia and its somewhat milder form, hypochondroplasia. Both are among the most common reasons for dwarfism. In affected people, the elongation of the long bones is impaired. As a result, the extremities are shortened. The bones are normally thick, and the trunk is nearly normal. In addition to dwarfism are also a pronounced hollow back with flattened vertebral bodies and a disproportionately enlarged head with a bulging forehead typical of achondroplasia.

Another skeletal dysplasia associated with dwarfism is osteogenesis imperfecta, better known as “vitreous bone disease”. Due to a disturbed collagen synthesis, the bones in those affected are unstable and often break. Depending on the severity, different types of osteogenesis imperfecta are distinguished. While patients with the mildest variant may still have an externally normal physique, the severe forms due to the numerous fractures lead to deformities and dwarfism.

Endocrine disorders

This group includes various hormonal disorders that can cause dwarfism. First of all, this is due to a lack of the growth hormone somatotropin. In addition, too high a dose of cortisol in the body, such as occurs in Cushing’s syndrome, impede growth. The thyroid hormones triiodothyronine (T3) and thyroxine (T4) are also important for proper growth. Therefore, a hypothyroidism in which too little of these hormones are produced, the reason for dwarfism.

Malnutrition

Without a sufficient and balanced food supply no normal growth can take place. In countries where many people suffer from lack of food, malnutrition is a common cause of dwarfism.

In Germany, the food supply is sufficient, but there are diseases that prevent the nutrients are properly absorbed from the intestine into the body. Typical causes of such Malabsorption are chronic inflammatory bowel disease (such as Crohn’s disease) and especially the celiac disease, which is an intolerance of gluten (gluten protein in cereals) is based. Permanent malabsorption during the growth phase leads to dwarfism as well as malnutrition.

Organic and metabolic causes

Also various disorders of the various organ systems and metabolic processes in the body can lead to dwarfism. These include primarily diseases of the heart, lungs, liver, intestine and kidneys as well as disorders of carbohydrate, fat, protein and bone metabolism.

Constitutional delay of growth and puberty

In some cases, dwarfism is only due to delayed biological ripening. The final size after completion of the growth phase is in the “latecomers” but in the normal range. This constitutional delay of growth has a hereditary component, so that often at least one parent was affected as a child.

Psychosocial causes

The impact of psychosocial circumstances on a child’s growth should not be underestimated. For example, mental neglect in the child can lead to a short stature, whereby the growth arrears can usually be made up again if the environment changes in time. The technical term for this type of neglect is Psychic Deprivation. Other mental causes of dwarfism may be eating disorders and depressive disorders.

Short stature: examination and diagnosis

Because there are so many potential causes of dwarfism, the diagnostic approaches are numerous and varied. First and foremost, the size of the patient must be determined and determined whether there is even a short stature. For this one considers the measured value in comparison with data of peers.

If there is a short stature in a child, the expected final size can be determined by means of an X-ray of the left hand. In this way, it may be possible to ascertain whether dwarfism is already congenital or whether a normal final size is to be expected, but growth is hampered by other diseases or deficiencies.

To get to the root of the problem, depending on the suspicion, the further diagnosis. This includes, for example:

• Measuring the height of parents and siblings to identify a possible family component
• Questioning the parents, whether they came to a late puberty development
• Search for other symptoms that are typical of chromosomal disorders or syndromic disorders. If there is a specific suspicion, a targeted molecular genetic examination of the genome is made.
• Examination and measurement of the skeleton for any disproportions
• detailed internal medical examination including a blood test, in order to determine about a deficiency or excess of relevant hormones
• Metabolism-specific diagnostics
• In children: Accurate nutritional analysis and determination of body weight and body mass index (BMI) to track down any malnutrition.
• In children: assessment of the interaction between parent and child, assessment of the psychosocial situation of the child

Short stature: treatment

The therapy of dwarfism depends on its cause. If it is the result of another underlying disease, an attempt is made to treat it. Many forms of dwarfism can not be treated at all or only inadequately. It is important in any case that the dwarfism is recognized as early as possible and you start immediately with a therapy. The sooner this happens, the better the results. Once the growth lines of the bones have closed, the body length can not be changed.

growth hormones

In some forms of dwarfism, it makes sense to administer artificial (recombinant) growth hormone, somatotropin or IGF as needed. This is the case, for example, if deficiency of these growth hormones is the reason for the short stature. But also for other causes such as the Ullrich-Turner syndrome, renal insufficiency or intrauterine dwarfism, the administration of growth hormones may be useful. This therapy approach may also have a positive effect on idiopathic dwarfism, but there is still no clear data on this to date.

Psychological care

Psychological care for short people and their family environment can help to accept the situation and to deal with it better. Those affected can also find help with the “Federal Association of Small-Growth People and their Families e.V” (BKMF).

Short stature: Disease course and prognosis

Dwarfism in itself does not necessarily have to be associated with health risks. Idiopathic dwarfism, for example, does not affect those affected further, apart from the small size. In achondroplasia, the increased stress on joints often leads to signs of wear, but life expectancy is not diminished. Osteogenesis imperfecta, on the other hand, is associated with a decreased life expectancy. If short stature is the symptom of another underlying disease, the prognosis ultimately depends on it.