Dwarfism

What is Dwarfism?

Dwarfism is a medical term used to describe someone who is shorter than average. It’s defined as someone whose height is below the standard or falls in the lowest 3% for their age and gender. When measuring height, it’s from the ground to the top of the head when the head is in a normal straight position. It’s worth noting, though, that many people dislike the term ‘dwarf’ and prefer to identify themselves as ‘Little People.’ There is even a community called the ‘Little People of America’.

Dwarfism can be divided into two main types, based on how a person looks: proportionate short stature (PSS) and disproportionate short stature (DSS). In proportionate short stature, the person’s limbs and body are equally smaller. On the other hand, in disproportionate short stature, there is a significant variation in the sizes of the limbs or trunk. The purpose of evaluating a child with dwarfism is to identify any specific causes of their short stature and provide the appropriate interventions or treatments.

What Causes Dwarfism?

Short height in kids can be either normal or due to a specific medical problem. Familial Short Stature, Constitutional Delay of Growth and Puberty, and Idiopathic Short Stature are examples of normal growth variations. Other causes are related to various health problems.

Familial Short Stature (FSS) occurs when a child’s expected height is lower because of their parents’ height. In these instances, the child grows normally and there’s no underlying medical problem causing their short height. X-ray of the hand and wrist can help determine the child’s projected height based on their bone growth.

Constitutional Delay of Growth and Puberty (CDGP) refers to children who are shorter in their early years but reach normal height in adulthood, often referred to as ‘late bloomers’. They also reach puberty later than their peers. Unlike in familial cases, these children’s bone age is less than their actual age. Causes could be poor nutrition during pregnancy or childhood, or even genetics.

Idiopathic Short Stature (ISS) is when there’s no known reason for a child’s short height. Recent research shows that numerous genetic mutations may explain many cases that were previously unexplained. Also, the role of epigenetics (how genes are turned off and on) in height issues is currently being explored.

Endocrine disorders like Growth Hormone Deficiency often cause dwarfism. Growth Hormones, which trigger bone and soft tissue growth, are regulated by the hypothalamus and pituitary gland. If these hormones are low, it can result in short height. Early puberty can also cause children to grow quickly at first, but then their bones mature early, resulting in shorter height in adulthood.

Various genetic disorders like Down’s Syndrome and Turner’s syndrome are associated with short height. This is just one of many symptoms seen in these conditions.

Short height can also be due to bone diseases. Achondroplasia is a genetic condition that prevents the normal development of cartilage into bone, specifically in the long bones. Spondyloepiphyseal dysplasia is a form of dwarfism that primarily affects the spine and the ends of the bones closest to the joint. The cause is an issue with a protein called collagen, but it’s unclear why only certain parts of the bone are affected.

Lastly, some medical conditions that affect the whole body can also cause short height. These include poor nutrition, arthritis, bowel diseases, kidney diseases, heart and lung diseases, immune problems, metabolic diseases, cancers, and certain medication therapies. These can affect a baby’s growth in the womb or a child’s growth, resulting in shorter height.

Risk Factors and Frequency for Dwarfism

In America, only 2.5% of individuals are short. The Utah Study, that examined growth in children, found that only a small number of short stature cases are caused by endocrine disorders. This condition affects individuals of both genders. However, boys are more likely to receive medical attention due to societal norms.

Different ethnic groups have different average heights, which is important to consider when making comparisons. Therefore, it is advised to only compare an individual’s height with people from the same group, if there are specific growth charts available. Malnutrition is a common cause of slowed growth in children, particularly in developing countries. The government and non-profit organizations are continuously working to address this issue.

• In America, 2.5% of the population are shorter than average.
• The Utah Study revealed that hormonal disorders only account for a small percentage of short stature cases.
• Both males and females can be affected, but boys are more likely to be taken to doctors due to social norms.
• Different ethnicities have different average heights, so it’s important to consider this when comparing height averages.
• One is advised to compare an individual’s height to their own ethnic group, if possible.
• Malnutrition can cause delayed growth in children, especially in developing countries.
• Efforts are underway by the government and non-profit organizations to address malnutrition.

Signs and Symptoms of Dwarfism

Understanding the cause of dwarfism requires a detailed medical history of the patient. This should cover everything from pregnancy to birth, including key growth stages and the onset of puberty. It’s also helpful to note if there are any family members who are shorter in stature. Since dwarfism can lead to social pressures and stress, a psychological evaluation of the patient is important. Regular measurements of body weight, height, torso height, and limb length are taken during pediatric appointments. These measurements are compared to typical growth patterns based on age, gender, and population group to identify any potential issues.

• Collection of detailed medical history from pregnancy to puberty
• Recording the family history of short stature
• Psychological assessment of the patient
• Regular measurements of body weight, height, torso height, and limb length
• Comparison of anthropometric measurements with average growth patterns

Testing for Dwarfism

The child being examined will undergo a set of biochemical and imaging tests:

The biochemical tests will check for a variety of things including:

• Diseases related to blood, such as anemia, by conducting a complete blood count.
• Cystic fibrosis through a sweat chloride test. Often, patients with this condition have had past issues with lung symptoms and blocked bowels.
• Hypothyroidism by checking the levels of serum TSH and free T4.
• Inflammatory bowel disease through a Wintrobe sedimentation rate test.
• Celiac disease through a test for several different types of antibodies.
• Signs of poor nourishment by checking the levels of serum pre-albumin and transferrin, which are usually low in malnourished people.

The imaging tests can help spot a few different conditions:

• An X-ray of the left hand and wrist can give predictions about bone age, which can help estimate future adult height. There are two different methods for doing this, one simpler and one more reliable.
• An MRI can help spot any growths in the brain or developmental problems with a gland in the brain called the pituitary. This is particularly checked before starting growth hormone therapy, to ensure there aren’t any organic lesions.
• Karytyping can identify genetic conditions like Down syndrome and Turner syndrome.

Additionally, the doctors may use provocative tests to measure growth hormone reserve. These tests have limited use, as they aren’t reliable and don’t offer a true reflection of how growth hormone is released naturally. These tests can involve giving injections of substances such as insulin or Levodopa, or even expose the child to certain natural stimuli like strenuous exercise or fasting. Growth hormone levels can naturally change throughout the day, making it an unreliable marker to determine growth hormone deficiency.

Therefore, doctors often look for other markers, like serum IGF-1 levels and IGFBP-3 levels for a more reliable diagnosis. However, in patients going through puberty, having brain tumors, or being malnourished, these markers can be high even if they do have a growth hormone deficiency and are, therefore, unreliable in such cases.

Treatment Options for Dwarfism

There are several treatment options available to children to help them achieve the best possible outcomes. These include:

Hormone Therapy

Recombinant human growth hormone therapy (rhGH) is a good treatment for children who aren’t growing as they should be due to a lack of certain hormones. Starting this treatment early can help prevent them from being much shorter than their peers and dealing with the mental stress that can come with it. However, it’s worth noting that there is debate around the benefits of rhGH, so the exact dosage kids receive depends on their weight. Newer research suggests that dosing rhGH based on children’s IGF levels could be safe and lead to better results. For kids who are short for unknown reasons (ISS), starting GH therapy can improve how fast they grow and their final adult height. Therefore, it might be fair to say that the decision to give rhGH doesn’t only depend on the reason for the short stature, i.e., whether it’s down to ISS or GHD but also on other factors such as the maturity of the growth plate, the height of the parents, etc. These factors can sometimes be unusually high, even in the presence of GHD, and are not reliable indicators.

Gonadotropin-releasing hormone (GnRH) analogs are used to stop the progress of early-onset puberty. When these analogs are given, they consistently suppress the release of hormones from the pituitary and the gonadal steroids, which were causing too-early bone maturation.

Surgical Treatment

Brain tumors need intervention from a brain surgeon. It’s important to note that procedures aimed at lengthening limbs are generally not recommended as they carry high risks of serious complications and death.

What else can Dwarfism be?

When it comes to possibly diagnosing dwarfism, doctors may consider a range of different conditions. These can involve the endocrine system, which regulates growth hormones. Conditions here can include a lack of growth hormone, congenital hypothyroidism, Cushing’s syndrome, or hypogonadism.

They may also take various genetic disorders into account. These include Down’s syndrome, Turner’s syndrome, Noonan’s syndrome, Prader-Willi syndrome, Russell-Silver syndrome, and diseases linked with the short stature homeobox gene deficiency.

Certain bone disorders, such as achondroplasia, diastrophic dysplasia, and spondyloepiphyseal dysplasia, can also affect a person’s height.

Lastly, dwarfism can be a symptom of a chronic condition. Some examples are chronic kidney deficiency, chronic malnutrition, cystic fibrosis, juvenile arthritis, inflammatory bowel disease, celiac disease, immune diseases, metabolic diseases, and certain cancers. It can also occur due to treatments with glucocorticoids.

Given the wide range of possible conditions, doctors must thoroughly examine every symptom and conduct several assessments to confirm a diagnosis.

What to expect with Dwarfism

People who are naturally shorter can expect to live healthy lives. Those with Growth Hormone Deficiency (GHD) can improve with treatment involving a synthetic version of human growth hormone. Starting this treatment before puberty often allows these patients to reach heights similar to their parents. However, if the short height is due to genetic or bone disorders, it can’t be reversed and will be a lifelong condition.

Possible Complications When Diagnosed with Dwarfism

Children who are shorter than average might be showing signs of a hidden ongoing disease and might need a complete medical check-up. These children often have less bone density compared to their taller peers, but it’s still unclear if this is linked to osteoporosis. Kids with disproportionate dwarfism often face other complications like bowed legs, arthritis, kyphosis (curvature of the spine), narrowing of the spinal canal, syringomyelia (a cyst in the spinal cord), sleep apnea, a buildup of fluid in the brain (hydrocephalus), and weight gain.

Hormone therapy to help kids grow can sometimes have complications, such as the potential for developing type-2 diabetes, benign pressure increase in the skull, water retention or carpal tunnel syndrome (a condition that affects the hand and wrist), displacement of the growth plate in the hip joint (SCFE), scoliosis (a sideways curve of the spine), and swelling of the breast tissue in boys before puberty begins. If these complications develop, the treatment might need to be stopped temporarily until the symptoms improve, and then restarted at a smaller dose.

Common Complications in Children with Dwarfism:

• Bowed legs
• Arthritis
• Kyphosis
• Spinal stenosis
• Syringomyelia
• Sleep apnea
• Hydrocephalus
• Weight gain

Possible Complications of Growth Hormone (GH) Therapy:

• Potential predisposition to type-2 diabetes
• Benign intracranial hypertension
• Edema/carpal tunnel syndrome
• Slipped capital femoral epiphysis (SCFE)
• Scoliosis
• Prepubertal gynecomastia

Preventing Dwarfism

It’s important that both patients and their family members understand the causes, underlying conditions, and treatment options for being shorter than average. For patients about to start growth hormone therapy, they should know the following:

The growth hormone used in treatment is very similar to the one naturally produced by our bodies and is both safe and effective. Within 6-8 weeks of starting treatment, the patient might notice their feet growing, an increase in appetite, gaining of muscle mass, and losing of fat.

Continual check-ups with a specialist in children’s hormones (a pediatric endocrinologist), blood tests, and X-rays are needed to keep track of the child’s development. The treatment is a long-term commitment, and sticking to the plan is crucial for achieving the best possible results.

Patients should also know how to administer the medication properly, where to inject it, when to take it, and how to store it correctly to make sure it remains effective.

There could be side effects, like allergic reactions, rashes, or swelling at the injection site. Pain in the hip, knee, or other joints could be a sign of a hip condition known as slipped capital femoral epiphysis. Headaches might be a indication of a harmless condition causing high pressure in the skull (benign intracranial hypertension). The treatment might also cause a curve in the spine to worsen (progression of scoliosis) or temporary increase in blood sugar levels. If any of these side effects occur, the treatment can be paused until the symptoms go away, and then restarted with a lower dose.