Achondroplasia: One of the Most Common Causes of Dwarfism

Achondroplasia is a problem in bone growth and is one of the most common causes of dwarfism making the person to have a short stature. According to the National Institutes Health, achondroplasia accounts for about 70 percent of all dwarfism cases. The condition affects about 1 in 25, 000 people.

Many health conditions can cause dwarfism. In fact, there are more than 200 different health problems that can cause dwarfism. Aside from achondroplasia, other health conditions, such as kidney disease and pituitary disorders, can cause the condition as well.

Achondroplasia is a genetic condition, which means that the condition may occur because of an abnormal gene. In some cases, the condition is inherited from a parent or both who have the abnormal gene, according to the Genetics Home Review (GHR) of the U.S. National Library of Medicine (NLM).

Achondroplasia is a Greek term which means "without cartilage formation." This, however, does not mean a person with the condition does not produce cartilage. The problem lies with the body having difficulty of converting the cartilage into bone.

Most bones of the body develop from a certain kind of cartilage. The cartilage is then converted to bone during development in the womb and continues to be replaced as the child grows. In people with achondroplasia, the conversion of cartilage into bone occurs very slowly, particularly in the long bones of the arms and legs.

Achondroplasia does not usually affect brain development. The GHR says that people with the condition generally are of normal intelligence. However, motor development may be delayed, such as sitting, standing, and walking.

Signs of achondroplasia include: having short arms and lower limbs, particularly the upper arms and thighs; limited movements at the elbows; bowed legs; and having an enlarged head and a prominent forehead. Typically, people with the condition have shorter hands. In adults with achondroplasia, their lower back develops a very prominent and often permanent sway called lordosis. In the medical field, this is called hyperlordosis. This can cause frequent back pains and can make walking difficult.

Other health problems that may be associated with achondroplasia include breathing problems such as apnea (breathing stops for short periods), obesity and ear infections.

The average adult height for males with achondroplasia is about 4 feet, 4 inches. In females with the condition, the average adult height is about 4 feet, 1 inch.

Currently, there is no cure for achondroplasia.

Sources:

Achondroplasia. Genetics Home Reference (GHR), U.S. National Library of Medicine (NLM).

Dwarfism. National Institutes of Health (NIH).

Questions and Answers: Achondroplasia. Office of Rare Diseases Research (ORDR), National Institutes of Health.