Although this condition can be inherited in an autosomal dominant manner, 80% of cases are due to new, sporadic mutations. Mutations involve the gene encoding fibroblast growth factor receptor 3 (FGFR3), situated on
chromosome 4
.
What gene or chromosome is affected by achondroplasia dwarfism?
Mutations in the FGFR3 gene
cause achondroplasia. The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. Two specific mutations in the FGFR3 gene are responsible for almost all cases of achondroplasia.
What type of chromosome mutation is achondroplasia?
What is achondroplasia? Achondroplasia is caused by
a gene alteration (mutation) in the FGFR3 gene
. The FGFR3 gene makes a protein called fibroblast growth factor receptor 3 that is involved in converting cartilage to bone. FGFR3 is the only gene known to be associated with achondroplasia.
How does achondroplasia affect the chromosome?
Achondroplasia is a single gene disorder
?
caused by
mutations
?
in the FGFR3 gene
?
on chromosome
?
4. Two different mutations in the FGFR3 gene cause more than 99 per cent of cases of achondroplasia. It is a dominant
?
genetic disease so only one copy of the FGFR3 gene needs to be mutated for symptoms to develop.
What chromosome is the FGFR3 gene on?
FGFR3, a tyrosine kinase receptor gene, is located at
chromosome 4p16. 3
and is composed of 19 exons [14]. The extracellular portion can bind with fibroblast growth factors, initiating cascades of downstream signals that ultimately influence cell growth, migration, angiogenesis, and differentiation [14].
What is chromosome number 4?
Chromosome 4 is
the fourth largest of the 23 pairs of chromosomes in humans
. Chromosome 4 is made up of over 186 million base pairs, the building blocks of DNA which are tightly packed and super coiled to from the DNA helix. Chromosome 4 represents around 6% to 6.5% of the DNA in the human genome.
What is achondroplasia dwarfism an example of?
Achondroplasia is a bone growth disorder that causes
disproportionate dwarfism
. Dwarfism is defined as a condition of short stature as an adult. People with achondroplasia are short in stature with a normal sized torso and short limbs. It’s the most common type of disproportionate dwarfism.
Is achondroplasia a disability?
Social Security has no dedicated listing for Achondroplasia
, but people suffering from the side effects of it can be disabled by pain and lack of functioning in the joints. Additionally, for children with growth problems, SSA does have rules which apply to a “failure to grow.”
How can achondroplasia be prevented?
Currently,
there is no way to prevent achondroplasia
, since most cases result from unexpected new mutations. Doctors may treat some children with growth hormone, but this does not significantly affect the height of the child with achondroplasia. In some very specific cases, surgeries to lengthen legs may be considered.
Who is most affected by achondroplasia?
Achondroplasia appears to affect
males and females
in equal numbers. This disorder begins in the developing fetus and is one of the most common forms of skeletal dysplasia that causes dwarfism. The estimated frequency of achondroplasia has ranged from about one in 15,000 to one in 35,000 births.
What is the life expectancy for a person with achondroplasia?
| Achondroplasia | Treatment Support groups, growth hormone therapy, treatment of complications | Prognosis 10-year shorter life expectancy | Frequency 1 in 27,500 people |
|---|
How does achondroplasia affect a person’s life?
Affected patients experience
various orthopedic and neurological complications
and might face multiple medical and non-medical challenges in their daily life [5,6,7,8]. Adult patients reported physical and mental impairments as well as lower quality of life and lower self-esteem than healthy relatives [9, 10].
At what age is dwarfism detected?
Disproportionate dwarfism is usually apparent
at birth or early in infancy
. Proportionate dwarfism may not be diagnosed until later in childhood or the teenage years if your child isn’t growing at an expected rate.
What does FGFR3 code for?
The FGFR3 gene provides instructions for
making a protein called fibroblast growth factor receptor 3
. This protein is part of a family of four fibroblast growth factor receptors that share similar structures and functions.
Where is FGFR3 found?
FGFR3 is a transmembrane tyrosine kinase receptor that binds fibroblast growth factors. The FGFR3 gene, located
on chromosome 4p16. 3
(Thompson et al. 1991), consists of 18 coding exons (Keegan et al.
What are the 4 chromosomal abnormalities?
Besides trisomy 21, the major chromosomal aneuploidies seen in live-born babies are:
trisomy 18; trisomy 13; 45, X (Turner syndrome); 47, XXY
(Klinefelter syndrome); 47, XYY; and 47, XXX. Structural chromosomal abnormalities result from breakage and incorrect rejoining of chromosomal segments.
