Achondroplasia

Achondroplasia is basically is of the most common forms of dwarfism. So obviously is marked by short arms, short legs, and a rather large forehead (frontal bossing). Midface hypotonia *decreased muscle tone* is another characteristic that is an obvious sign, especially in childhood. Spinal curvatures are also common. Motor skills are usually delayed, but life span and intelligence are usually normal. Though in rare cases, this deformity could block an infant’s airway or cause compression on the spinal cord.

This pathology is due to genetics believe it or not! Well, to be more specific, a mutation a certain gene; to be even more specific, the gene FGFR3. So in order to detect this certain mutation, ‘molecular genetic testing’ must be done. This testing is in fact 99% efficient in detecting this mutation. Another form of diagnosis includes radiology, such as CT or MRI. But if it is undetectable in these modalities, then the molecular genetic testing would be done.

This condition is irreversible, but there are ways of monitoring it. It is important to monitor height, weight, and head circumference. It is also important for MRI and CT evaluation to make sure there is no spinal cord compression or severe hypotonia.

Interesting to know, out of the children who are diagnosed with achondroplasia, 80% have both parents of normal stature, which means that the gene mutations or mostly spontaneous. But if a parent has the condition, the infant has a 50% of inheriting it. If both parents have it, the infants chances are increased to 75%.


Below is a T1 weighted MRI image of an infant with achondroplasia. notice the distinct frontal bossing.http://radpod.org/wp-content/uploads/2007/03/achondroplasia_arrows.jpg

Below is a father and a son out exercising, both diagnosed with achondroplasia.http://www.sciencemuseum.org.uk/on-line/genes/images/1-3-5-1-4-2-1-1-1-0-0.jpg