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 General Info about Achondroplasia |
| What are the causes of Achondroplasia? |
| What are the symptoms of Achondroplasia? |
| How is Achondroplasia diagnosed? |
| How is Achondroplasia treated? |
| More valuable information |
| Frequently asked questions |
| Glossary |
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| General Info about Achondroplasia |
Achondroplasia is a disorder of bone growth. Achondroplasia literally means "without cartilage formation" . The problem in this condition is converting the cartilage into bones, particularly the long bones.
Achondroplasia is a genetic (inherited) condition that results in abnormally short stature. Achondroplasia sufferers are 'little people'. The average height of an adult with achondroplasia is 131 cm (52 inches, or 4 foot 4) in males and 124 cm (49 inches, or 4 foot 1) in females.
Achondroplasia is one of the oldest known birth defects. An average figure worldwide is approximately 1 in 25,000 births.
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| What are the causes of Achondroplasia? |
Mutations (chemical changes) within a single gene cause achondroplasia. The condition may be passed on from one generation to the next or it may result from a new mutation in a gene from average-sized parents.
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| What are the symptoms of Achondroplasia? |
 An individual with achondroplasia has disproportionately short stature: the head is large with prominence of the forehead and the arms and legs are short when compared to the trunk length. This is particularly noticeable in the upper arms and thighs.
The baby's fingers appear short and the ring and middle fingers diverge giving the hand a trident (three-pronged) appearance.
The baby exhibits some decrease in muscle tone (hypotonia). Because of the large head, especially compared to rest of the body, and the decreased muscle tone, the child with achondroplasia will be behind "schedule" in reaching the usual motor milestones.
Enlargement of the brain called Megalocephaly is common and normal with achondroplasia.
At birth there is often prominence of the mid-to-lower back with a small hump. With walking, the hump goes away and a pronounced sway of the lower back becomes apparent. The legs are bowed.
A protruding jaw, with sometimes poor dental structure is seen. The teeth are crowded and the upper and lower teeth may be poorly aligned.
Another sign is "double" jointedness, caused by lax (loose) ligaments in some joints. Many achondroplastic children can flex their finger, wrist, hip, and knee joints to an extreme degree because of this ligamentous laxity.
Middle ear infections are frequent and can lead to mild to moderate hearing loss.
Older children and adults frequently experience fatigue, numbness, or pain in the lower back and thighs.
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| How is Achondroplasia diagnosed? |
The diagnosis of achondroplasia can be based on the typical physical features, the hallmarks of achondroplasia that are evident at birth.
Characteristic features are also seen on x-rays, ultrasound and other imaging techniques.
Diagnosis before birth is accomplished by examining cells of the body. A DNA test of those cells can also confirm achondroplasia obtained by a procedure called chorionic villus sampling (CVS) or amniocentesis.
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| How is Achondroplasia treated? |
At present there is no specific treatment to promote growth in achondroplastics. When special problems complicate achondroplasia, prompt and expert intervention is important.
The large opening under the skull should be surgically enlarged in cases of severe narrowing and compression of the spinal cord.The spinal cord compression can require surgery to decompress it.
Orthopedic procedures may be required for lengthening of the limb bones and correction of bowed legs.
Teeth should be straightened and, if necessary, removed to alleviate the problem.
Control of obesity is essential. Adults with achondroplasia should also monitor and control their weight because excess weight aggravates back and joint problems.
Growth-hormone treatment seems to increase the rate of growth during the first year of treatment, but may not increase adult height.
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| More valuable info... |
In 1994 Dr. John Wasmuth and his colleagues discovered that a mutation of the fibroblast growth factor receptor-3 (FGFR3) gene on human chromosome 4 causes achondroplasia.
As early as 1912 it was noted that new cases were more often last-born than first-born children. This fits with the fact that the chance of an achondroplastic birth has been shown to increase with paternal age (age of the father).
Intelligence is entirely normal in patients with achondroplasia.
Mothers carrying babies with achondroplasia should have their babies delivered by cesarean birth, as there are chances of bleeding within the baby's head during vaginal delivery.
Complications may include:-
Hydrocephalus (Disproportion between the brain and the base of the skull can sometimes result in hydrocephalus "water on the brain").
Club feet.
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| Frequently asked questions |
Which doctor can I consult if my baby has achondroplasia?
You can consult a pediatrician, orthopedic surgeon, dental surgeon and a neuro surgeon.
What can be done for patients with achondroplasia?
Children and adults with achondroplasia can lead normal lives provided they receive attentive, informed care by their physicians and parents.
My spouse and I both have achondroplasia. What is the probability that we will have a child of average stature?
The chances are 25 percent, or 1 in 4 .
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| Glossary |
Achondroplasia- short stature adults below 131 cm in males and 124 cm in females. They have problem formation of the cartilage.
Genetic- inherited
Megalocephaly- enlargement of the brain
Hypotonia - decrease in muscle tone |
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