Achondroplasia
Achondroplasia is a genetic bone disorder responsible for the most common form of dwarfism. It occurs in approximately 1 out of every 20,000 births. People with this condition are of normal intelligence but are of abnormally short stature, with disproportionately short arms and legs, and a larger head than usual. In most cases, individuals with achondroplasia, although they experience a number of physical and psychological challenges, are fully functional and live out a normal life span.
Causes of Achondroplasia
Although the condition may be inherited, it most often occurs as a spontaneous mutation, meaning two parents without the condition can produce an affected child. If one parent has achondroplasia, the child has a 50 percent chance of inheriting the disorder. If both parents have the condition, the risk of the child being affected rises to 75 percent. If an infant inherits the abnormal gene from both parents, the offspring does not usually survive for more than a few months.
Characteristics of Achondroplasia
Achondroplasia is observable at birth, or even prenatally. Before birth, the disorder may be evidenced by excessive amniotic fluid surrounding the fetus. At birth, the infant with achondroplasia presents with a head which is abnormally large front-to-back. There may sometimes also be signs of hydrocephalus (water on the brain). By observing X-rays of the newborn's long bones, the condition may be definitively diagnosed. Apart from the body build and larger-than-normal head, individuals with achondroplasia may also have:
- Crowded teeth
- Curved lower spine
- Spinal stenosis
- Flat feet and bowed legs
- Large space between 3rd and 4th fingers
- Decreased muscle tone
- Prominent forehead
Complications of Achondroplasia
The characteristic abnormalities of achondroplasia can lead to a number of complications, so it is important for individuals with the condition be be under ongoing medical care. People with this disorder are more prone to obesity, breathing difficulties and frequent ear infections than the general population. They also often develop significant arthritis and back problems, including spinal cord compression, later in life and may require surgery for extreme curvature of the upper spine at some point.
Because of their obvious variations from the norms of physical appearance, people with achondroplasia suffer varying degrees of psychological stress in social situations. In childhood, and particularly in adolescence, the stress may be especially severe. Coupled with the difficulties of maneuvering in a world suited to other people's physical proportions, life can be extremely difficult for people with achondroplasia. Individuals most often require psychotherapy and some form of group support to make a comfortable adjustment.
Treatment of Achondroplasia
Currently, there are two controversial treatment possibilities for achondroplasia: growth hormone therapy and lengthening, both attempts to normalize appearance and function. Neither has been accepted by Little People of America, the nonprofit organization representing people with achondroplasia and similar conditions.
Although both growth hormone therapy and lengthening of the long bones in the legs and arms have been successful in some cases, they are both fraught with uncertain outcomes and potentially serious complications. Lengthening of the femur (large leg bone) or humerus (long arm bone) are both complex procedures involving tremendous pain and prolonged incapacity. The operations have to be performed in childhood or early adolescence, and many fear that the physical and emotional trauma of the procedures may outweigh any future benefits. Moreover, these operations, which involve cutting the bones and inserting a device called a fixator between them, do not always achieve the desired results. Growth hormone therapy is also a somewhat questionable solution since it does not work equally well for all patients or at all stages of treatment.
While each treatment has its advocates, both types of treatment are rejected by many on the basis that the disabilities people with achondroplasia experience are clearly surmountable and, at least at the present time, medications or operations to "normalize" people who are different are unnecessary and dangerous.