What is short stature?
Short stature is a general term used to describe a condition in which a child or a teen’s height is well below the average height of his or her peers. Short stature typically means that a person’s height is below that of the shortest 3 per cent to 5 per cent of children of the same age and sex. Short stature could be idiopathic (with no known cause), an inherited trait or a symptom of one of several underlying disorders. Many disorders can cause short stature, including achondroplasia, hormone deficiency, delayed puberty, Cushing’s disease, malnutrition, malabsorption disorders, such as celiac disease, and others. A child must be examined by a health care provider if short stature is suspected or present.
Types of short stature
There are different types and causes of short stature or restricted growth, and they will present differently. Because the range of conditions is so broad, restricted growth can be classified in various ways.
One categorization is:
- Variant restricted growth
- Proportionate short stature (PSS)
- Disproportionate short stature (DSS)
- Each of these categories includes several types and causes of short stature.
Variant restricted growth
Sometimes a person is small but otherwise healthy. This can be referred to as variant restricted growth. It may happen for genetic or hormonal reasons. If the parents are also small, this can be called familial short stature (FSS). If it stems from a hormonal issue, it is a constitutional delay in growth and adolescence (CDGA).
The limbs and the head develop in proportion with the spine, and the individual is otherwise healthy.
Growth happens throughout the body, so the legs, for example, are in proportion with the spine.
In most cases, the individual’s parents are also small, but sometimes small stature happens because the body does not produce enough growth hormone (GH), or the body does not process growth hormone properly. This is known as GH insensitivity. Hypothyroidism can lead to low hormone production.
Proportionate short stature (PSS)
Sometimes, overall growth is restricted, but the person’s body is in proportion, and the individual has a related health problem. This is known as proportionate short stature (PSS). If the individual is heavy for their height, this can suggest a hormone problem. The problem could be hypothyroidism, excess glucocorticoid production, or too little GH.
A person who is small and their weight is low for their height may be experiencing malnutrition, or they may have a disorder that leads to malabsorption.
Whatever the underlying reason, if it affects overall growth, it may impact development in at least one body system, so treatment is needed.
During adulthood, a person with this type of restricted growth is more likely to experience:
- Cardiovascular problems
- Reduced muscle strength
- Rarely, there may be cognitive problems or problems with thinking. This depends on the cause of the short stature.
Disproportionate short stature (DSS)
Disproportionate short stature (DSS) is linked to a genetic mutation. The parents are usually of average height. As with other types of short stature, a range of underlying causes is possible. An individual with DSS will be small in height, and they will have other unusual physical features. These may be visible at birth, or they may develop in time as the infant develops.
Most individuals will have an average-sized trunk and short limbs, but some people may have a very short trunk and shortened, but disproportionately large limbs. Head size may be disproportionately large.
Intelligence or cognitive abilities are unlikely to be affected unless the person has hydrocephalus or too much fluid around the brain.
Achondroplasia underlies around 70 per cent of cases of DSS. It affects around 1 in 15,000 to 1 in 40,000 people.
- An average-sized trunk
- Short limbs, especially the upper arms and legs.
- Short fingers, possibly with a wide space between the middle and ring fingers.
- Limited mobility in the elbows
- A large head with a prominent forehead and flattened bridge of the nose.
- Bowed legs
- Lordosis, progressive development of a swayed lower back.
- Average adult height of 4 feet, or 122 cm.
Causes of short stature
The top 3 reasons for short stature are constitutional growth delay, genetics, and disease.
Constitutional growth delay
Some children simply develop later than others. These kids are small for their age and often enter puberty later. However, they’ll continue to grow after their friends have stopped. They usually catch up by adulthood.
If one or both parents are short, there’s a strong possibility that their child will also be short. If there are no underlying medical reasons why either parent is short, their child’s short stature may be perfectly healthy.
Several diseases can cause unusually short stature. These diseases are divided into several categories.
Endocrine diseases: Endocrine diseases affect hormone production, and often height. These include:
- Growth hormone deficiency (GHD)
- Hypothyroidism (low thyroid hormone levels)
- Cushing’s disease
Chronic diseases: Some chronic diseases can also decrease height due to their effects on general health. Examples include:
- Heart disease
- Inflammatory bowel disease (IBD)
- Kidney problems
- Sickle cell anaemia
- Juvenile idiopathic arthritis (JIA)
- Genetic conditions that affect height include Down syndrome, Turner syndrome, and Williams syndrome.
- Bone and skeletal diseases: These diseases, such as rickets or achondroplasia, can change height due to their effects on bone growth.
- Problems during pregnancy can also affect a child’s height. Malnutrition can also cause short stature. However, growth problems caused by malnutrition are rare in the United States.
Symptoms of short stature
Short stature does not cause any symptoms other than the obvious finding of short height. If there is an underlying disorder present, there may be symptoms related to that condition.
A physical exam followed by measurement of height, weight, arm, and leg length is the first step in the diagnosis. Next, family history questions will be asked, which will give clues as to whether short stature could be the result of inherited disease. The child’s medical and physical history will also be detailed. X-rays and blood tests are usually ordered to determine whether the short stature is due to mere growth retardation or a more complex condition.
Treatment of short stature
Treatment for short stature depends on the underlying cause. For instance, if the cause is a chronic disease, such as diabetes or sickle cell anaemia, these conditions should be treated first.