Last Updated on September 11, 2022
Dwarfism implies short stature that usually results from slow or delayed growth caused by some medical or genetic condition. [Dwarfism is known to be caused by about 200 distinct medical conditions.] It is an adult height of 4 feet 10 inches or under, as a result of a medical or genetic condition.
The average height of an adult with dwarfism is 4 feet.
However, short stature in the absence of a medical condition is not generally considered dwarfism.
Dwarfism can lead to various issues like
- Abnormal bone alignment
- Early degenerative joint disease
- Exaggerated lordosis or scoliosis
- Spinal stenosis
- Reduced thoracic size
- Nerve compressions
- Affect on skull structure and growth of the brain, severely impairing mental capacity.
Achondroplasia and growth hormone deficiency are responsible for the majority of dwarfism cases.
The term short stature is also used to describe the condition.
Classification
Dwarfism can be classified as
- Disproportionate when the body size is disproportionate
- Proportionate when the body is small to the same degree and appears to be proportioned like a body of average stature.
Disproportionate Type
This is the common type of the two. Most people with dwarfism have disorders that cause disproportionately short stature.
Usually, this means that a person has an average size trunk and very short limbs, but some people may have a very short trunk and shortened (but disproportionately large) limbs.
The other common characteristic of these disorders is that the head is disproportionately large compared with the body. Example – achondroplasia
Almost all people with disproportionate dwarfism have normal intellectual capacities.
Proportionate Type
Proportionate type results from a medical condition present at birth or appearing in early childhood that affects overall growth and development.
Therefore, the head, trunk, and limbs are all small, but they are proportionate to each other. Because these disorders affect overall growth, many of them result in poor development of one or more body systems.
Growth hormone deficiency is a relatively common cause of proportionate dwarfism. It occurs when the pituitary gland fails to produce an adequate supply of growth hormone.
A primordial dwarfism is a type that results in smaller body size in all stages of life beginning from before birth. The individuals are extremely small for their age, even as a fetus.
Locationwise Types
This type of classification names the dwarfism as per the location of the body parts involved.
To understand this classification we need to understand the following
- Root refers to proximal parts. These include thupper arms and thighs
- The middle part refers to the leg/forearm as the middle part
- The hands/feet are referred to as the end.
Therefore, accordingly, dwarfism can be
- Rhizomelic : Involving bones of the upper arm or thigh
- Mesomelic : Involving bones of the forearm or leg
- Acromelic : Involving bones of hands and feet.
It is called micromelic when the entire limbs are shortened.
Causes of Dwarfism
There are be various causes that lead to shortened stature.
Dwarfism can be due to disorders of cartilage, bone, or vertebrae
Achondroplasia
The most recognizable and most common form of dwarfism in humans is achondroplasia, accounting for almost 70 percent cases.
It produces rhizomelic short limbs, increased spinal curvature, and distortion of skull growth.
The limbs are proportionately shorter than the trunk (abdominal area) whereas the head and facial features are larger.
Achondroplasia is a mutation in the fibroblast growth factor receptor resulting in inhibiting bone growth.
Spondyloepiphyseal Dysplasias
Spondyloepiphyseal dysplasia refers to a group of conditions characterized by a shortened trunk, which may not become apparent until a child is between 5 and 10 years old.
Other features can include club feet, cleft palate, severe osteoarthritis in the hips, weak hands and feet and a barrel-chested appearance
Diastrophic Dysplasia
A rare form of dwarfism [1 in 100,000 births], that results in mesomelic shortening. Other signs can include deformed hands and feet, limited range of motion, cleft palate and ears with a cauliflower appearance.
Growth hormone Deficiency [Pituitary Dwarfism]
It is a medical condition in which the body produces insufficient growth hormone [somatotropin]. Children with this disorder may grow slowly and puberty may be delayed by several years or indefinitely.
This growth hormone deficiency can be caused by
- Gene mutation
- Damage to the pituitary gland
- Turner’s syndrome,
- Poor nutrition,
- Stress
Other Important Causes
- Pseudoachondroplasia
- Hypochondroplasia
- Noonan syndrome
- Osteogenesis imperfecta
- Hypothyroidism.
Diagnosis
The most common forms are caused by genetic mutations of bone and cartilage and can be detected when fetus is still developing .
But these tests are carried in high risk cases only. For example when the condition runs in the family.
However, most of the cases of the short stature are born to parents of normal height and therefore most of the cases are only evident after the birth.
After the child is born, diagnosis of achondroplasia, diastrophic dysplasia, or spondyloepiphyseal dysplasia can be confirmed through physical examination, x-rays and genetic testing.
Also, in some cases, the short stature doesn’t become evident until later in a child’s life.
Extreme shortness with completely normal proportions sometimes indicates growth hormone deficiency (pituitary dwarfism). Following investigations help to confirm this cause
- Medical examination
- Growth hromone levels
Management
Dwarfism is neither a disease nor a disability. But the conditions leading to dwarfism can lead to various other issues which need to be addressed.
Short stature that is below average can be a psychological and social issues for the child as well as the adult. But as we know most of the causes of short stature cannot be coorected . Hence once identified we neeed to accept the condition.
Psychosocial Issues and Their Care
Genetic defects of most forms of dwarfism caused by bone dysplasia cannot be corrected. Therapeutic interventions are typically aimed at preventing or reducing pain or physical disability, increasing adult height, or mitigating psychosocial stresses and enhancing social adaptation.
Medical Treatment
Forms of dwarfism associated with the endocrine system may be treated using hormonal therapy.
Pain and disability may be treated by
- Physical therapy
- Braces
- Surgical procedures
- Shunt insertion to drain excess fluid from the brain
- Tracheotomy to improve breathing through small airways.
- Corrective surgeries for deformities
- Spine decompression surgeries
- Distraction osteogenesis for bone lengthening
- Shoe lifts for altering the perceived height or better self-image.
Psychosocial Support
Parents with short statured children should inculcate independence and self-esteem from the beginning.
Changes can be made to make things easier for their height so that they have a sense of self-reliability.
remain calm to the negative comments from other people. Help to nurture unique qualities of your child.
Stay active and prefer those family activities that your child can unite.
Find support groups for older children so that the children have a sense of belonging and get motivated to become achievers like others.
References
- Wit JM et al. Idiopathic short stature: definition, epidemiology, and diagnostic evaluation. Growth Horm IGF Res. 2008 Apr;18(2):89-110. – Link
- Ornitz DM, Legeai-Mallet L. Achondroplasia: Development, pathogenesis, and therapy. Dev Dyn. 2017 Apr;246(4):291-309.
- Quitmann JH, Bullinger M, Sommer R, Rohenkohl AC, Bernardino Da Silva NM. Associations between Psychological Problems and Quality of Life in Pediatric Short Stature from Patients’ and Parents’ Perspectives. PLoS One. 2016;11(4):e0153953. Link
