Dwarfism is a short stature associated with a medical or genetic condition. Generally, a dwarf is defined as an adult with a height of 4 feet 10 inches or less. Averagely, the height of a dwarf is 4 feet.
The two broad categories of dwarfish are:
- Disproportionate dwarfism– some body parts are above-average, average or below-average. It is caused by disorders that inhibit bone development.
- Proportionate dwarfism– the body parts are usually small to the same degree with a proportionate appearance of average body stature.
It is evident in people with disorders that cause disproportionate short stature whereby a person possesses an average short trunk and shorter limbs. Some of the people with disproportionate dwarfism may have a very short trunk and shortened but large limbs. The head is usually larger in comparison with the body.
Disproportionate dwarfism normally comes with normal intellectual abilities except rare cases where caused by a secondary factor like hydrocephalus (excess fluid around the brain).
Achondroplasia is a common disorder causing disproportionate growth, and it results in the following signs:
- Short legs and arms where the upper legs and upper arms are particularly short.
- A mean-size trunk.
- Short fingers accompanied bya wide separation between the ring and middle fingers.
- The elbows have limited mobility.
- Adult height of 122cm.
- Bowed legs develop progressively.
- Swayed lower back grows progressively.
- Disproportional large head with a flattened bridge and prominent forehead.
Other than achondroplasia, disproportionate dwarfism may also be caused by a rare disorder known as spondyloepiphyseal dysplasia congenita (SEDC), whose signs include:
- A short neck
- A short trunk
- The average size of feet and hands.
- Cheekbones appear slightly flat.
- Arms and legs are short.
- A broad rounded chest.
- Adult height of between 91 cm to just above 122cm.
- Hearing and vision impairment.
- Instability of bones of the neck.
- Twisted or out of shape foot.
This disorder is a result of medical conditions acquired at birth or that appear in early childhood that cause limitation of overall development and growth. Therefore, the trunk, head, and limbs appear all small and proportionate to one another.
The relative common cause of proportionate dwarfism is growth hormone deficiency, whereby the pituitary gland does not produce adequate amounts of the growth hormone vital for normal growth at the childhood level. The signs associated are:
- A slower growth rate that is lower than the expected for a given age.
- Delayed or lack of sexual development at teen years.
- Height under the standard pediatric growth charts.
Other causes of dwarfism.
Turner syndrome is a condition affecting women and girls only that results when the X chromosome is partially or completely missing. The X chromosome is acquired from each parent; therefore, a girl with Turner syndrome possesses just one fully functioning female sex chromosome and not two.
Dwarfism arises from deficiencies in hormones, genetic disorders, and poor nutrition. In some cases, the cause is usually unknown.