dwarfism



OVERVIEW

Definition

Dwarfism is defined as height that is more than 2 standard deviations (-2SD) below the average height of a normal healthy population of the same race, age, and sex, or below the 3rd percentile of the growth curve of the normal population in similar living situations.

Formerly known as dwarfism, it is no longer used because of its pejorative overtones.

Incidence

The prevalence of dwarfism in Chinese adolescents and children is about 3%.

There are about 7 million children between the ages of 4 and 15 who need treatment for dwarfism, but less than 30,000 children with dwarfism receive treatment each year.

Classification

Children are categorized according to their body type as follows.

Well-proportioned with normal growth rate.

Well-proportioned with a slow growth rate.

Disproportionate.

Disproportionate body shape with cosmetic deformities.

Causes

Causes

Common Causes

Genetic and metabolic influences are present at every stage of growth.

Growth and development are also influenced by endocrine, nutritional, chronic diseases and social environment.

Adverse factors at any stage of growth and development can cause growth to slow down or stagnate, deviating from the normal process of growth and development, which can eventually lead to short stature.

Causes of Different Types of Dwarfism

The etiology and mechanism of dwarfism will be different for different body types, as described below.

Idiopathic dwarfism: such as somatic growth retardation or delayed puberty, familial dwarfism, etc., the etiology of which is currently unclear.

Small for gestational age: caused by maternal, fetal, placental and other related factors, including low birth weight normal length, low birth weight short length and normal birth weight short children.

Systemic diseases: such as cardiovascular diseases, malabsorption or gastrointestinal diseases, pulmonary diseases, renal diseases, chronic liver diseases, immune diseases, malignant tumors and infectious diseases.

Endocrine diseases: such as growth hormone deficiency dwarfism, hypothyroidism, Turner syndrome, Laron syndrome, precocious puberty.

Drug effects: such as long-term use of hormone therapy, long-term use of insulin therapy.

Mental factors: e.g. long-term mental depression or tension, serious emotional deficits, etc.

Skeletal and metabolic diseases: such as vitamin D deficiency rickets, vitamin D-dependent rickets, renal rickets, anti-vitamin D rickets, Fanconi syndrome, renal tubular acidosis, congenital osteogenesis imperfecta, chondrodysplasia, macroglossia, etc.

Inborn metabolic disorders: e.g. glycogen storage disease, mucopolysaccharide storage disease, etc.

Chromosomal abnormalities, e.g., Down’s syndrome, etc.

Symptoms

The main manifestation is a lower than expected height or length.

Typical symptoms

Height or length is less than 2 standard deviations from the average height of the healthy population, or the 3rd percentile of the growth curve, for the same race, age, and gender.

Growth and development may be normal or slow.

Body size may be proportional or non-proportional.

Accompanying Symptoms

May be accompanied by abnormalities of sexual development, such as delayed development, premature development, hypoplasia of secondary sexual characteristics, and reproductive deficits.

Skeletal developmental abnormalities, such as abnormal size and shape of limbs, spine, and skull bones, may be present.

It may be accompanied by mental retardation, such as demented face and delayed motor development.

It may be accompanied by facial abnormalities, such as infantile face (baby face), large head, small face, saddle nose, low nose bridge, blue sclera, demented face, and so on.

It may be accompanied by obesity.

May be accompanied by symptoms of the primary disease, such as loss of appetite, emaciation, fever, cough, tetany, convulsions, bone fracture.

Consultation

Department of Medicine

Endocrinology

If the following symptoms occur, it is recommended that you seek medical attention.

Short stature or delayed growth compared to normal people of the same race, sex and age.

Delayed sexual development, premature development, or underdevelopment of secondary sexual characteristics.

Presence of mental retardation, facial abnormalities such as large forehead, wide/narrow eye spacing, and flat nose.

Preparation for medical consultation

Preparation for consultation: registration, preparation of documents, FAQs

Tips for Medical Consultation

It is recommended to record the change in height for the doctor’s reference.

Preparation Checklist

Pay particular attention to the time of onset of symptoms, special manifestations, etc.

Is the child shorter than his/her peers?

Does the child roll over, crawl, walk and talk normally during growth?

Does the child have any blood relatives with short stature?

Does the child have allergies to medications, foods, or other substances?

Are there any diseases such as obesity, diabetes, high blood pressure, hypothyroidism, or brain tumors?

Test results in the last six months, which can be brought to the doctor’s office

Laboratory tests: blood test, liver and kidney function, urine test, electrolytes, blood gas analysis, blood growth hormone, insulin-like growth factor 1, growth hormone stimulation test, thyroid hormone, chromosome karyotype analysis

Imaging tests: bone age X-ray, cranial CT, cranial magnetic resonance imaging

Other tests: electrocardiogram

Medication use in the last 3 months, bring the box or package with you to the doctor’s office if available

Recombinant human growth hormone, human growth interleukin, alpha-osteol, osteotriol, calcium carbonate, calcium gluconate

Diagnosis

Diagnosis is based on

Medical History

During the mother’s pregnancy, there may have been viral infections and malnutrition, and the fetus may have been functionally delayed and smaller than gestational age.

At birth, there may be craniocerebral injury; presence of small for gestational age.

After birth, there may be nutritional deficiencies, failure to achieve catch-up growth, and delayed sexual development.

The patient may have a past history of chronic illness, use of certain types of medications, and psychosocial and cognitive developmental disorders.

The patient’s parents may have slow pubertal growth, and short stature may run in the family.

Clinical manifestations

The main manifestation is short stature with or without developmental abnormalities.

The body shape may or may not be proportional, and the proportions of the body parts may be abnormal.

Facial features may be abnormal, such as a large forehead, wide and narrow eye spacing, large eye lobes, flat nose, and demented face.

There may be abnormalities in intelligence.

Symptoms related to other diseases may also be present.

Measure the proportions of the upper and lower body, as well as other organs, to check for abnormal body shape.

The head, face, trunk, and limbs are examined for specific signs.

Measurement of height and weight, as well as calculation of the percentile at which the measurements fall.

Annual rate of growth in height (observed for at least 3 months or more).

Measurement of target height in adulthood based on the height of the patient’s parents.

Calculation of body mass index (BMI), BMI = weight (kg)/height squared (m²).

Patients entering puberty or adulthood need to be staged for sexual development.

Infant and pediatric patients need to be examined for time of tooth eruption, number, and alignment.

Intelligence test is performed if necessary.

Laboratory Tests

Routine blood tests: check for anemia, malnutrition, chronic infection, malignancy, leukocytosis, leukopenia, etc.

Erythrocyte sedimentation rate, C-reactive protein: can indicate the presence of infectious diseases, malignant tumors and so on.

Liver and kidney function: suggesting the presence of liver and kidney dysfunction.

Urine routine: used to determine whether there is renal dysfunction, renal tubular acidosis, etc.

Electrolyte and blood gas analysis: to indicate whether there are disorders of body fluid and acid-base balance, renal tubular acidosis, etc.

Blood growth hormone, insulin-like growth factor 1, insulin-like growth factor binding protein 3, growth hormone stimulation test: to understand the growth hormone function, to determine whether there is growth hormone disorder.

Prothrombin time: to assess vitamin K status.

Carotene: to assess the status of vitamin A.

Thyroid hormone: to assess the presence of hyperthyroidism or hypothyroidism.

Other endocrine hormone tests: This test is required when endocrine factors are considered based on the patient’s clinical presentation, including blood adrenocorticotropic hormone, cortisol, sex hormones, and blood glucose.

Chromosomal karyotype analysis: This test is required if chromosomal abnormalities (Down syndrome, etc.) are considered.

Imaging

Bone age X-ray: It is determined that bone development occurs throughout the entire growth and development process, and is a good indicator for assessing the development of an organism.

Cranial CT or MRI: suggests the presence of cranial diseases such as hypothalamic-pituitary tumors and congenital midline defects.

Differential diagnosis

Differential diagnosis of various causes of dwarfism is needed.

Somatic growth retardation or delayed puberty

Similarities: both have short stature.

Difference: somatic growth retardation tends to have a family history. Body shape is proportional, growth rate is normal, birth weight is normal, growth is slow before puberty, growth and development increases to puberty and can reach normal level; intelligence is normal.

Familial dwarfism

Similarities: Both have short stature.

Differences: Familial dwarfism is characterized by short stature of the parents, normal growth rate, bone development and sexual development, and normal endocrine function.

Hypothyroidism

Similarity: Both are characterized by short stature.

Differences: Familial short fetuses are prone to term births and have abnormal growth after birth; children with onset of short stature after 2 years of age have less intellectual ability and less obvious changes in appearance. Thyroid function tests are often abnormal.

Growth hormone deficiency dwarfism

Similarity: both have short stature.

Difference: growth hormone deficiency dwarfism mostly develops after 1 year of age, with the increase of age, the more obvious backwardness of growth and development; childish face, baby face, intellectual development is mostly normal. Growth hormone testing is often suggestive of insufficient secretion; secondary cases may have pituitary gland and nearby tissue lesions, and imaging tests are helpful in the diagnosis.

Vitamin D deficiency rickets

Similarity: both have short stature.

Differences: Vitamin D deficiency rickets can appear in the early stage of irritability, worry, sweating, shaking the head and other manifestations, and abnormal development of bones, with the growth and development of short stature symptoms gradually, easy to fracture. Laboratory tests can find slightly lower blood calcium, lower blood phosphorus, calcium-phosphorus product <30, lower serum 25-(OH)D3, increased blood alkaline phosphatase, X-ray examination can find abnormal bone development.

Renal rickets

Similarity: Both have short stature.

Difference: renal rickets has a history of renal damage. Symptoms are similar to those of vitamin D deficiency rickets. Laboratory tests may reveal decreased blood calcium and increased blood phosphorus, and renal function tests and imaging may reveal abnormalities.

Glycogen storage disease

Similarity: Both have short stature.

Differences: Patients tend to have type I glycogen storage disease, with onset in infancy. Patients are characterized by hepatomegaly, growth retardation, short stature, nosebleeds, increased stool frequency, baby face, relatively thin limbs, and a few hypoglycemic convulsions; intellectual development is mostly normal. Laboratory tests may reveal hypoglycemia, acidosis, elevated blood lactate, lipids and uric acid, and abnormal liver function; liver tissue biopsy or ultrasound may reveal hepatic abnormalities, and DNA test may reveal abnormalities.

Mucopolysaccharide storage disease

Similarity: both have short stature.

Differences: patients with mucopolysaccharide storage disease are mostly normal at birth, but after 1 year of age, they have short stature, ugly face, large head, low nose, large nostrils, thick lips, prominent forehead and cheekbones, hairy and low hairline, short neck, bone and joint deformities, and backward intellectual development. Laboratory tests may reveal positive urine mucopolysaccharides, X-rays may reveal abnormal bone development, and enzyme analysis and DNA analysis may confirm the diagnosis.

Treatment

Aim of treatment: alleviate symptoms and actively treat underlying diseases.

Treatment principle: choose different treatment measures according to different causes.

Short stature is a symptomatic manifestation of many diseases, and effective treatment measures can only be formulated after the cause of the disease has been clarified.

For patients with dwarfism, the cause of the disease should be actively lifted or the primary disease should be treated. After the cause of the disease is lifted or improved, the symptoms of short stature will naturally improve.

If the dwarfism is caused by chronic diseases, the primary disease should be treated first, and the specific treatment should be based on the cause of the disease.

If the dwarfism is caused by long-term use of glucocorticoids or other drugs, if necessary, under the guidance of a doctor to change the drug program.

If dwarfism is caused by mental factors, the patient’s family, school and social environment should actively participate in the treatment and provide adequate care to the patient.

General treatment

Monitor growth and development, record height, weight and sexual development.

In terms of diet, strengthen the nutritional supply, pay attention to a balanced diet, and take more protein and calcium-containing food.

For exercise, if your condition permits, you should do exercise as appropriate, and outdoor exercise is preferred.

As for sleep, it is recommended to go to bed early and get up early. It is recommended to go to bed before 11:30 a.m. and have at least 7 hours of sleep every day.

Parents are advised to pay more attention to their children and give them enough security and care.

Those treated with growth hormone should be followed up every 3 months.

Patients need to have regular tests for IGF-I, T4, TSH, blood glucose and insulin, liver and kidney function, and check bone age annually.

Patients with intracranial lesions need regular brain MRI.

Patients with osteoporosis should reduce the amount of exercise appropriately, and should pay attention to their own protection to avoid fractures.

Medication

Growth Hormone

Growth hormone is the only effective drug approved by the FDA for the treatment of childhood dwarfism.

The overall growth hormone treatment should follow the principle of individualization, using early treatment, adequate dosage and long course of treatment.

The dosage forms are powder and water, daily and weekly. The method of daily preparation is subcutaneous injection every night before bedtime; the therapeutic dose is related to the type of disease, pubertal status, IFG-1 level, etc., and should be used under the guidance of a doctor.

The therapeutic effect is dose-dependent and varies among individuals.

The duration of growth hormone treatment should be determined according to clinical indicators and indications for discontinuation of the drug, and should not be shorter than 1 to 2 years.

The use of recombinant human growth hormone, occasional pain, numbness, redness and swelling at the injection site, but also joint pain, sodium retention and other adverse effects can be seen, and should be carefully observed after use.

Some patients may develop hypothyroidism, which needs to be corrected and reviewed in time.

Patients with intracranial tumors or intracranial trauma need to pay attention to regular review when using growth hormone.

Human growth hormone

Growth intermediates act directly on bones, thus promoting growth and development.

It is effective in the treatment of Laron type syndrome and is also a promising drug for the treatment of pituitary dwarfism.

Growth Hormone Releasing Factor

Acts on the hypothalamus to stimulate the pituitary gland to secrete growth hormone.

This hormone can be used both to check pituitary function and for treatment.

Various hormones

If various hormone deficiencies are present, targeted hormone supplementation is required.

In patients with hypothyroidism, thyroid hormone supplementation is required.

In patients with gonadal hormone deficiency, sex hormones may be added at the onset of puberty.

Other medications

During treatment, trace elements such as calcium and phosphorus should be supplemented according to one’s condition in order to improve substances for bone development.

Patients with all types of rickets and Fanconi syndrome are treated with supplements of 1,25-(OH)2-D3, as well as calcium or phosphorus.

Electrolyte disorders need to be corrected if acidosis is present in patients with dwarfism.

Patients with glycogen storage disorders require glucose supplementation if hypoglycemia occurs, as well as dietary therapy.

Surgery

Surgery should be considered if fractures occur as a result of osteoporosis and if the condition is severe.

If there are deformities of bone development (e.g., inversion, eversion, fusion of bone and vertebrae), surgical correction should be considered if necessary.

If surgical treatment is required in the course of allopathic treatment or treatment of the primary disease, this treatment needs to be considered.

Prognosis

Cure

The possibility of cure is related to the etiology of the disease and whether or not there is early intervention.

In terms of etiology, short stature may be cured if the cause can be completely resolved or cured; conversely, short stature may persist and not resolve spontaneously.

In terms of early intervention, the earlier the treatment, the less impact it will have on height in adulthood; conversely, short stature is likely to persist in adulthood.

Harmfulness

Patients with chronic disease are prone to irreversible pathological changes in the skeleton.

Patients with dwarfism may have intellectual backwardness and mental retardation, and are prone to lack of self-care ability.

Patients with dwarfism may have backward sexual development, which may affect normal sexual life and reproductive ability.

Prolonged disease states can lead to psychological disorders.

Daily

Daily Management

Diet

Diet needs to pay attention to nutritional balance.

It is recommended to eat more food rich in high quality protein, such as eggs, milk, lean meat, fish and shrimp, soybean products.

It is recommended to take appropriate supplements of food containing calcium and phosphorus, such as milk, soybean products, shrimp skin, deep-sea fish, shellfish, sesame seeds, nori and so on.

It is recommended to eat more fresh fruits and vegetables.

Replenish enough water daily, it is recommended that 1,000 to 2,000 milliliters per day is appropriate.

Lifestyle Habits

Make it a habit to monitor and record growth and development such as height, weight and sexual development, and synchronize the information to the doctor during follow-up visits.

Pay attention to regular review, patients and family members need to actively cooperate with the doctor’s treatment.

Exercise appropriately when physical conditions permit, and outdoor exercise is recommended; exercise can promote bone growth and development.

In terms of sleep, develop the habit of going to bed early and try to go to sleep before 11:30 p.m. Do not stay up late and go to bed late, so as not to affect the hormone levels in the body.

Psychologically, patients should look at the disease correctly, have confidence in the treatment, avoid too much negative emotions, and seek help from family, friends and psychologists when necessary.

The patient’s family should pay attention to care for the patient, give the patient enough support and encouragement, and have patience and confidence in the patient.

Rehabilitation

Patients with backward intellectual development and mental retardation should actively participate in special education and behavioral training to improve self-care ability.

Patients with dwarfism who have suffered from bone fracture need to undergo rehabilitation as early as possible, and carry out joint mobilization and functional exercises as early as possible.

Prevention

In terms of life, parents should ensure the child’s nutrition during the growth and development period, ensure sufficient exercise and sleep, and also pay attention to the child’s psychological care.

In case of disease, the child should go to the hospital in time and receive regular treatment under the guidance of the doctor; regular check-ups are required during the treatment period.

Couples with a family history of dwarfism are advised to undergo genetic counseling and prenatal diagnosis before family planning to avoid the disease in the next generation.

Parents should pay close attention to their children’s growth and development, and seek early treatment when abnormalities occur. Early intervention can minimize the adverse effects.

Some cases of dwarfism cannot be prevented and the prognosis needs to be improved through early detection, early diagnosis and early treatment.