Pediatrics

Short stature

definition

By definition, short stature, also known as short stature, is when the body length or size is below the 3rd percentile of the growth curve. This means that at least 97% of their peers in the general population are taller. For example, if a child is in the 2nd percentile, 98% of children of the same age are taller and 2% shorter than this. For adults, once they have finished growing, only their height, regardless of age, is decisive. Currently, the limits of short stature for adults are 150 cm for men and 140 cm for women.

When does one speak of short stature?

By definition, one speaks of short stature when growth occurs below the third percentile.

Adults are said to be less than 150 cm long.
In many cases the cause is familial or constitutional, but in some cases the short stature is a sign of a chronic, possibly genetic disease.

It is important that population-specific reference values for growth are used for the diagnosis.
The average values for the growth in length of a child who comes from Canada are different from one who is born and grows up in the Netherlands.

causes

The causes of short stature are very diverse. However, the most common is the familial short stature, in which there is no growth disorder. The child's parents are small, so it is to be expected that the child conceived will be small compared to the general population. However, the growth must be regular and proportionate, i.e. the proportions of body to limbs etc. must be within the normal range.

The second most common cause is constitutional growth retardation. This is characterized by a slower growth rate and especially a delayed entry into puberty. The growth phase is extended so that the target size genetically determined by the parents can be achieved. Parents are often already aware of a delayed entry into puberty.

Also read on this topic: Stunted growth

Much rarer are hormone deficiencies, e.g. Hypothyroidism, underproduction of growth hormone, or chronic diseases are the cause. Chronic diseases particularly include those that make it difficult to absorb nutrients, e.g. inflammatory bowel disease or gluten-related celiac disease.

In addition, a wide variety of genetic diseases can lead to a reduced body size. These can be inherited from the parents, even if they are not affected by it, or if they appear again.

In addition, malnutrition, neglect, and abuse can also lead to decreased growth.

Inheritance

As already mentioned, the height of the child is largely predetermined by the height of the parents. A target size for the child can be calculated using the parental height, although the final height of the child is subject to certain deviations from this calculated. This results in the familial short stature, which, however, is not a disease per se. The following formula is used to estimate the final height: (height father + height mother +13 cm (for boys) or -13 cm (for girls) / 2.

Read more on this topic at: Body size determination

On the other hand, genetically determined diseases can be passed on to the children, the inheritance path of the disease then plays a role and determines the likelihood of the child ultimately falling ill and thus also being short. This varies greatly from illness to illness and can be assessed by a specialist in human genetics.

Short stature syndromes

There are various genetic syndromes that can cause short stature. This is very well known Achondroplasia, the most common skeletal disease in which the ossification of cartilage and thus bone growth is disturbed. This disorder is inherited in an autosomal dominant manner, but in the majority of cases it is due to a new mutation, i.e. the parents were neither sick nor carriers of the genetic change. In this disease, the expected body length is less than 130 cm, the trunk reaches a normal length and primarily the limbs are too short because the long bones do not develop sufficiently. The head looks disproportionately large.

Another disease that, depending on the severity, can lead to short stature is the so-called Glass bone disease (osteogenesis imperfecta). In this disease there is a disturbed production of collagen, which is important for bone formation and stability. Depending on the severity of the disease, this leads to very brittle bones and disproportionate short stature. The inheritance of this disease depends on the type, although the various types differ in their severity.

What types of short stature are there?

There are innumerable forms of short stature, the most common of which are listed below:

The most common type of short stature in Germany in terms of percentage is family stature, in which the parents of the short child are roughly the same height.
This is calculated by dividing the height of the father and mother by two +6.5 cm for a boy and -6.5 cm for a girl.
Following the frequency comes the constitutional short stature, in which one finds a delayed growth rate.
A child can also be stunted psychosocially, for example through neglect or abuse of a child.
Hormonal disorders, chronic diseases or malnutrition can lead to reduced growth.
Hereditary diseases and syndromes that are associated with short stature should also be mentioned. Hereditary diseases are those whose causes are hereditary.
In addition, certain noxious substances such as alcohol and nicotine damage a child's growth in the long term. Therefore, during pregnancy, the mother should pay attention to a responsible lifestyle.
With the resulting embryo-fetopathies (diseases in which the child is damaged during pregnancy), the children are born very young and often also suffer from a failure to thrive with problematic weight gain.

When is short stature in babies to be assessed critically?

In principle, the reduced growth in height should not be viewed as critical.
It is important to consider the background and accompanying illnesses.

The most common cause of short stature worldwide is malnutrition. In this case, the child is not given essential foods for a long time.
It is also essential to examine whether a short baby has anemia or a heart defect that is affecting growth.

If there are signs of neglect or abuse, the youth welfare office must be involved in the case.

Is short stature a disability?

Short stature per se is defined as a height below the third percentile. This is mostly due to the fact that the growth period is shortened or the growth rate is slower compared to the normal population.
Short stature usually becomes noticeable in toddlerhood or puberty.

The question of whether there is a disability or not depends first of all on the cause of the short stature.

If the short stature is familial or constitutional, the children grow below the normal range, but normally.
If the short stature is due to a chromosomal aberration, a prenatal disorder, a hormone disorder or a chronic illness, further regulations for determining the degree of disability apply.
Second, the degree of disability in short stature depends on the proportionality of the body structure.
Malformations of limbs or joints, extraordinary wear and tear of joints due to a disproportionate body structure, restricted muscle function and the influence on the psychosocial situation are also assessed.

In summary, it can be said that short stature in most cases does not constitute a disability and in individual cases a decision must be made on a possible degree of disability.

Concomitant symptoms

The symptoms that are included in a genetic syndrome can be very diverse and depend on the underlying cause of the disease.

In the Achondroplasia In addition to the disproportionate growth, spinal canal stenosis often occurs. Other changes in the spine include increased chest kyphosis and lumbar lordosis. Leg misalignments also occur, e.g. Knock knees or bow legs. A protruding nose bridge and a diminished expression of the midface make for a very prominent forehead. In addition, these people tend to be more susceptible to infections of the upper respiratory tract and the middle ear.

In the Osteogenesis imperfecta Many fractures occur due to the fragility of the bones, even with minor trauma such as a fall from a low height. In addition, it can lead to hearing loss and a blue discoloration of the leather skins of the eyes.

Does short stature change life expectancy?

Basically, short stature is reduced body length, which has no effect on lifespan.

Particularly in the case of family-related short stature, one assumes a life expectancy equal to that of the normal population.
If the short stature is a sign of another chronic disease, the life expectancy of this disease must be taken into account.

For example, if there is a serious heart defect, it is likely that that person's lifespan will be more limited.
The same goes for severe forms of malnutrition and toxic damage during pregnancy from smoking, drugs, and alcohol.

Many hereditary syndromes (hereditary) and osteogenesis imperfecta (glass bone disease) are also associated with a reduced life expectancy.

It should also be mentioned that with some disproportionate forms of short stature, an unphysiological stress on the joints with premature wear is to be feared.

All in all, one can say that a short stature does not primarily lead to a reduced life expectancy. The decisive factor for the prognosis is the individual reason for the short stature.

diagnosis

The diagnosis of short stature is usually made by the pediatrician. In the course of the child's development, there are various statutory health check-ups. For this, the weight and height of the child are entered in the child's examination book. This results in a development process and you can create a growth and weight curve that can be compared with other children.

If the course is atypical, for example if the weight remains the same or the speed of growth slows down, the doctor should carry out further examinations to find the cause. This includes, on the one hand, further measurements to determine the proportionality of growth (body proportions), but also other investigations, e.g. Laboratory tests, for example to reveal hormone deficiencies or nutrient deficiencies. Depending on the patient's symptoms, other and further examinations may also be necessary, e.g. in the case of gastroenterological admission disorders or genetic, if there is evidence of a genetic disease.

Body size determination

The length of the biological parents is important for the expected height determination in adulthood.
The genetic target size is calculated from the body length father + mother / 2 and then + 6.5 cm for boys and -6.5 cm for girls.
An X-ray of the left hand is then used to calculate the bone age based on the bone maturity stages.
The proportions of the body are determined while sitting.
In addition to these examinations, it is also useful to examine certain laboratory parameters in the blood, for example to determine the hormone status.

Read our article on this: Determination of the final height

When is it possible to notice short stature?

Even prenatally, the gynecologist observes the growth and the proportionality of the child's body structure throughout the pregnancy.

After the birth, the growth of body length, weight and head circumference is recorded at regular intervals by the pediatrician during the preventive examinations using percentile curves. Such growth records must be kept over a long period of time. Therefore, a meaningful assessment can only take place after about two years.

The bone age, usually determined radiologically on the left hand, is preferably examined in the first year of life by an X-ray examination of the left knee and compared with the biological age.

Treatment / therapy

Treatment and therapy for short stature are heavily dependent on the cause. In the case of the familial short stature already mentioned, no treatment is necessary per se. Even if puberty is delayed, the genetic target can be achieved without treatment.

This is different with diseases that cause short stature. Deficiencies can be remedied with replacement therapies. This is important in the event of a hormone or vitamin deficiency. However, also with general malnutrition.

Diseases secondary to short stature should be treated to address the cause. This may be enough to restore normal growth. If this is not enough, however, growth-promoting drugs or hormones can be given in order to still achieve a greater body length.

Some genetic diseases lead to a short stature through a lack of certain hormones. Replacement therapy can also be considered here. In some cases, however, a parent-appropriate size cannot be achieved if they are of normal height.

In addition, however, there are diseases in which conservative therapies do not lead to promising growth. This is the case, for example, with achondroplasia.

Hormone treatment

If the short stature is based on a hormonal disorder, then under certain circumstances and circumstances hormone treatment for therapeutic purposes can be considered.

The doctor responsible for this, the pediatric endocrinologist, will perform a number of important laboratory and physical examinations.
Examples of a hormonal disorder can be an impairment of the pituitary function with insufficient production of growth hormones, or an underactive thyroid.

The medication used to treat short stature is the growth hormone “Growth Hormone”, which only has a beneficial effect on the growth in length while the child is still growing bones.
Using the hormone after the child has finished growing is therefore not corrective. It is for this reason that determining the age of the bones through an X-ray examination is so important.

Since the therapy can also have negative effects on the health of the child, the indication must be made strictly by the pediatric endocrinologist.
Side effects that should be mentioned are that pathological glucose tolerance and an underactive thyroid can develop.

Short stature and pregnancy

The development of the fetus during pregnancy is extremely important. At this stage, harmful substances such as nicotine or alcohol can not only lead to malformations and mental impairment, but also lead to long-term growth disorders. The children are not only born with a lower birth weight, but the growth process can also be impaired.

In addition, other maternal factors can also restrict the growth of the fetus in the womb. These include high blood pressure, diabetes mellitus, impaired kidney function, nutritional deficiencies and anemia, but also drug abuse. If a child is too light and small at birth due to these factors, a large part of this lack of growth still catches up, but with a smaller proportion this growth retardation persists and leads to a smaller final height.