Achondroplasia (Dwarfism)
Biology Research Project
Introduction
I chose to do achondroplasia because my little cousin Mason Coffey who is in the 6th grade has this condition.
Definition
A form of short limbed dwarfism. In early development bones are still mostly cartilage. Ossification is the process that converts cartilage to bone. This is the problem that Achondroplasia (dwarfism) has, the cartilage doesn't convert correctly especially in the long bones of the arms and legs causing the short stature that is evident in people with dwarfism.
Jason Acuna
You may know him as "Wee Man" from jackass.
Bill Klein and Wife Dr. Jen Arnold
Stars of the reality show "The Little Couple"
(From Left to right) Matt, Amy, Zach, Jacob, Molly, Jeremy.
The family from "Little People Big World"
Symptoms
- short stature
- short arms and legs
- Average height for females is 4'1'
- Average height for males is 4'4'
- limited range of motion at elbows
- enlarged head
- prominent forehead
- short fingers
Common Problems
- obesity
- recurrent ear infections
- lordosis (pronounces and permanent sway of the lower back)
- Kyphosis (abnormal front to back curvature of the spine)
- bowed legs
Facts I Learned
- Achondroplasia is the most common type of short limbed dwarfism.
- about 80% of people with this condition have normal sized parents.
- 1 in every 200,000 are affected by dwarfism.
- Dwarfs have the same life span as normal adults.
- occurs equally among races and genders.
- doesn't relate to location.
http://ghr.nlm.nih.gov/condition/achondroplasia
Causes
in 90% of cases dwarfism occurs as the result of a new spontaneous mutation in genetic material or it can be inherited.
How it is inherited
In normal sized parents achondroplasia occurs from mutations in the FGFR3 gene. In other cases the FGFR3 gene is inherited from one or both affected parents. It is inherited in an autosomal dominant pattern (the mutation occurs on the autosomes) . It is a non sex-linked disease. It is dominant.
Genes associated with Achondroplasia
FGFR3 Gene: Provides instructions for making proteins that are involved in the development and upkeep of bone and brain tissue.
Treatments
There is no cure for dwarfism, but there are treatments to help relieve some of it's effects.
Corrective surgeries: Cleft palate, club foot, and bowed legs.
Physical therapy can help strengthen muscles and increase joint range of motion.
http://www.webmd.com/children/dwarfism-causes-treatments?page=3#1
Diagnosis:
Achondroplasia can be confirmed through genetic testing, but can also be diagnosed at birth or infancy through a physical exam. However sometimes it goes unnoticed until later in a child's life and then exams are done.
Punnett Square
Genotype "TT" is a dwarf, Genotype "Tt" is a dwarf but a carrier of the normal gene, and genotype "tt" is normal.
achondroplasia
Carys and George's story - a Genetic Disorders UK / Jeans for Genes Day film