Growth & Stature Disorders: Causes, Diagnoses, Treatments, & Outlook

As a parent, if your child isn’t growing as they should be, it’s natural to worry about the possibility of growth disorders. Even though these disorders often require long-term treatments, most children can still live regular lives with them, even into adulthood.

If you’re concerned about your child’s lack of growth, though, learn the common signs to look out for and the most common treatment plans for each disorder.

Causes & Types of Growth Disorders?

An imbalance of hormones or genetic issues, such as abnormal chromosomes, are the most common causes. Sometimes, children might also be born with abnormal hormonal glands or skeletal deformities, the effects of which continue into adulthood.

Since genetics determine 80% of adult height,[1] it’s no wonder that genetic defects can cause short stature. Hormones also stimulate bones to grow and encourage a healthy metabolism, and any hormonal imbalances can inhibit growth and cause other disorders.

Growth disorders can be either inherited or developed, and we can roughly divide them into a few key categories:

Familial Short Stature – Short parents produce short children. Familial short stature isn’t a disorder but a genetic tendency to follow the trend of short height that runs in the family.

Constitutional Growth Delay – Constitutional growth delay means that a child is shorter than average pre-puberty or enters puberty at a later age than expected, which means they’ll experience puberty-related growth spurts later than the typical ages of 8-14.[2]

These children tend to reach the same height as their peers when they start puberty.

Small for Gestational Age – About 27% of all babies are born Small for Gestational Age (SGA) in low- and middle-income countries.[3] Genetic factors, placement of the fetus inside the womb, or the mother smoking or drinking alcohol during pregnancy can all cause this condition.

These babies are born with abnormally low length and weight, but most reach standard measurements by the time they’re 2.

Endocrine Diseases

Endocrine diseases are disorders caused by an imbalance in hormones. In most cases, discrepancies in Human Growth Hormone (HGH) production and thyroid hormone cause these disorders.

Growth Hormone Deficiency (GHD)

GHD is a pituitary disorder that occurs when a child’s body doesn’t produce enough HGH to facilitate growth. HGH signals bones to grow by converting growth plates (soft cartilaginous structures at the ends of long bones) to solid bone. GHD inhibits this growth and results in short stature by the time children reach adulthood.

GHD can result from either an underdeveloped pituitary gland (which produces HGH) that a child may be born with or glandular trauma caused by head injuries, brain infections and tumors, or pituitary tumors.

Another cause of GHD may be the hypothalamus, which is a part of the brain that controls the pituitary gland, not producing enough Growth Hormone Releasing Hormone (HGRH).[4]

Thyroid Disorders

The thyroid hormone regulates metabolism (how the body utilizes food and energy), but it also affects growth factors. In youth, lack of thyroid hormone, or hypothyroidism, can cause children to be shorter than they would otherwise be as adults.

Acromegaly

Acromegaly is the opposite of GHD – it occurs when the body produces too much HGH. Children with acromegaly can grow to an abnormally tall stature, leading to heart and bone problems and malnutrition. This condition is also appropriately known as Gigantism.

Precocious Puberty

Some children may enter puberty at abnormally young ages, like below eight years old. Early puberty results in them overgrowing and becoming much taller than children their age and gender for some time. Still, they’ll stop growing at a younger age and eventually end up shorter.

Congenital Problems

Congenital issues are conditions a child is born with, and these problems might occur in either the growth tissues, bones, or chromosomes.

Turner Syndrome (TS)

TS mainly affects girls and causes them to fail to develop during puberty. Girls with TS tend to be about 20 cm shorter than they should be as adults,[5] and it affects 1 in every 25,000 females.[6]

Girls with TS may also suffer from other conditions like heart and kidney diseases. Scientists believe that this syndrome occurs because of the absence of the Short Stature Homeobox-containing gene (SHOX) on the X chromosomes.[4]

Silver-Russell Syndrome (SRS)

SRS is a rare genetic condition where children are born much smaller than average and may have characteristic facial features like a triangular face. These children’s body parts will grow at different rates, and they won’t catch up to their healthy peers by two years of age.

This condition might occur from an imbalance in Insulin Growth Factor-2 (IGF-2), as well as a chromosomal abnormality.[4]

Skeletal Dysplasias

Skeletal dysplasias affect bone and cartilage growth and occur in about 1 in every 5,000 children.[7] These can have multiple hormonal and genetic causes and may, in turn, cause neurological problems in children suffering from them.

Dysplasias usually result in unequal, short limbs. Some body parts might grow as expected, while others will grow slower, making the patient look disproportionate.

Some dysplasias occur because of chromosomal anomalies or lack of aggrecan, a protein that enables the cartilage to bear weight. Still, these aren’t the only things that can result in skeletal dysplasias.

Prader-Willi Syndrome (PWS)

PWS is another rare disorder that occurs when the hypothalamus is underdeveloped. This disorder happens when some genes on chromosome 15 are atypical or missing and affects 1 in 10,000 to 30,000 worldwide.[8]

Children with PWS tend to be small in stature and have difficulty feeding in infancy, but they develop an abnormal appetite in childhood, leading them to eat dangerous objects. Later, they can even develop scoliosis and obesity, further inhibiting their growth.

Noonan Syndrome (NS)

NS can occur from a mutation on any of several separate genes. About half of all people with NS have an abnormality on chromosome 12. Though they may be born at an average length and weight, 83% of all children with NS will fall behind during puberty and have short stature as they become adults.[8]

Children with NS may also suffer from heart defects, unusual facial features like wide-set eyes and drooping eyelids, poor eyesight, and skeletal deformities.

Idiopathic Short Stature

Idiopathic short stature encompasses all growth delays and disorders which don’t have any apparent cause. Idiopathic comes from the Greek “idios” or “one’s own” and pathos or “cause”, which means these diseases don’t have any known cause.

Other Chronic Conditions

Chronic conditions like diabetes, kidney disease, and malnutrition can also cause short stature. Proper nutrition with lots of protein, calcium, and vitamin D is necessary for children to reach their full genetic height, so improper nutrition and chronic conditions that cause nutrients not to be absorbed correctly can cause slow or abnormal growth.

Growth Disorder Symptoms

The primary symptom of disorders that affect stature is delayed growth. If a child isn’t growing at the same rate as the peers of their age and gender, it could be worth looking into or scheduling a doctor appointment. The same concerns apply to children growing too fast for their age, though this may not be a problem unless a hormone imbalance causes it.

Generally, if a child falls into the bottom 3rd percentile for their age by height, it’s safe to say they need to be checked by a doctor.[4] A child falling from the 90th percentile to the 50th percentile might also cause concern even if they’re not too short for their age.

It’s essential to consider the parents’ heights and family history before reaching any conclusion, though. A child in the 5th percentile by stature may not have growth failure if their parents are also in the 5th percentile.

Diagnosing Various Disorders

Growth disorders are generally diagnosed by checking hormone levels and bone age, as well as tracking growth.

• Observing the child’s height for several months and comparing it with growth charts is usually the first order of business. The pediatrician might call parents and children at regular intervals to record the child’s height and weight and recommend further tests if the growth trend is abnormal.
• Blood tests can check for hormone imbalances and chromosomal disorders.
• X-rays of the bone can determine the “bone age” or skeletal maturity. Usually, the doctor will perform an x-ray of the left hand and wrist to see whether the growth plates which allow bones to grow are still open. Once they’re closed, children won’t grow any longer.[4]
• Examining the pituitary gland to check hormone levels.

Growth Disorder Treatments

Doctors will usually prescribe children with delayed growth or HGH deficiency somatotropin or HGH injections. These injections are given daily and can be pretty expensive but are effective for treating short stature caused by Turner Syndrome, babies born SGA, Prader-Willi Syndrome, and skeletal dysplasias.[4]

Other than HGH, doctors may also prescribe growth factors like IGF-1.[9] In case of a tumor on the brain’s pituitary gland, doctors may carry out radiation and chemotherapy. Once the tumor is gone, growth might return to normal.

Once individuals reach adulthood, they have the option to become taller with stature lengthening or limb lengthening surgery. There’s been a few examples online where the disorder resulted in dwarfism and patients underwent surgery to get taller (and fix knock knees or bow legs in some cases).

Outlook

Children who are shorter than their peers might suffer psychological distress from teasing or bullying by their peers. However, treatments like HGH therapy are time-consuming and require daily injections, so parents should consider whether their children can handle the stress.

Overall, though, many children without other symptoms may grow up to be confident in their stature and have a usual quality of life unless they suffer from other conditions like skeletal deformities. It’s best to discuss any concerns with a healthcare professional and observe the child’s attitude towards their height before starting treatment.

References

[1] MedlinePlus. (2020, September 17). Is height determined by genetics? MedlinePlus. https://medlineplus.gov/genetics/understanding/traits/height/

[2] NHS. (2018, November 16). Stages of puberty: what happens to boys and girls. NHS. https://www.nhs.uk/live-well/sexual-health/stages-of-puberty-what-happens-to-boys-and-girls/

[3] Black R. E. (2015). Global Prevalence of Small for Gestational Age Births. Nestle Nutrition Institute workshop series, 81, 1–7. https://pubmed.ncbi.nlm.nih.gov/26111558/

[4] Ergun-Longmire, B., & Wajnrajch, M. P. (2020). Growth and Growth Disorders. Endotext. https://www.ncbi.nlm.nih.gov/books/NBK279142/

[5] Reddy Danda, V. S., Sreedevi, P., Arun, G., & Rao, P. S. (2017). Growth Hormone Treatment in Turner’s Syndrome: A Real World Experience. Indian journal of endocrinology and metabolism, 21(3), 378–381. https://pubmed.ncbi.nlm.nih.gov/28553590/

[6] National Organization for Rare Disorders. (2019). Turner Syndrome. NORD. https://rarediseases.org/rare-diseases/turner-syndrome/

[7] Orioli, I. M., Castilla, E. E., & Barbosa-Neto, J. G. (1986). The birth prevalence rates for the skeletal dysplasias. Journal of medical genetics, 23(4), 328–332. https://pubmed.ncbi.nlm.nih.gov/3746832/

[8] Noditropin. (2021). Types of Growth Disorders: Noonan Syndrome. Norditropin. https://www.norditropin.com/about-growth/types-of-growth-disorders/noonan-syndrome.html

[9] Ali, O., & Wyatt, D. (2011). Therapy of growth disorders. Current opinion in endocrinology, diabetes, and obesity, 18(1), 3–8. https://pubmed.ncbi.nlm.nih.gov/21150587/