Achondroplasia- Dwarfism. By: Melissa Findlay. Who is most likely to get Achondroplasia?.
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Achondroplasia is an autosomal dominant condition. This means that an achondroplasic child can be born from one of the three possible ways. The first is if one of the parents has the disorder and the other is a big person. In this case there is a fifty percent chance that the child will be born a little person and a fifty percent chance that it will be born a big person.
If both parents are little people they would have also have a fifty percent chance of having an Achondroplasic child. However they would only have a twenty five percent chance of having a big person. The other twenty five percent would be born homozygous dominant. These children are said to have homozygous Achondroplasia. This condition is almost always lethal in the first year of life and virtually all are spontaneously aborted at birth.
The last possible way of having a child with this disorder is when two big people give birth to a little person. Seventy five percent of the little people living today came about due to this process. This process is known as a new mutation and occurs when the sperm is somehow develops into carrying the achondroplasic allele. Once this happens it is just as if one of parents is carrying the gene
Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism. It can be inherited as either a sex linked trait or a autosomal dominant trait, which means that if a child gets the defective gene from one parent, the child will have the disorder
All people with Achondroplasia have a short stature. The average height of an adult male with Achondroplasia is 131 centimeters (52 inches, or 4 feet 4 inches), and the average height of an adult female with Achondroplasia is 124 centimeters (49 inches, or 4 feet 1 inch).
An average-size trunk.
Short arms and legs with particularly short upper arms and thighs.
An enlarged head (macrocephaly) with a prominent forehead.
Fingers are typically short. The ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance.
People with Achondroplasia are generally of normal intelligence.
If you have a parent with dwarfism, It is strongly encouraged you and your short statured parent to have a genetic consult. By testing the parent or family member with dwarfism, they would have a better idea of which genes you might or might not be carrying.
A large number of the cases of Dwarfism are also due to random mutations with no family history. Genes that can be passed on, but not in either parent.
Currently, there is no way to prevent or treat Achondroplasia, since the majority of cases result from unexpected new mutations. Treatment with growth hormone does not substantially affect the height of an individual with Achondroplasia. Leg-lengthening surgeries may be considered, in some very specialized cases.