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 is achondroplasia on?
Achondroplasia results from specific changes (mutations) of a gene known as
fibroblast growth factor receptor 3 (FGFR3)
.
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 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.
Where does achondroplasia happen?
People with achondroplasia are short in stature with a normal sized torso and short limbs. It’s the most common type of disproportionate dwarfism. The disorder occurs in
approximately 1 in 25,000 live births
, according to Columbia University Medical Center (CUMC). It’s equally common in males and females.
What body systems are affected by achondroplasia?
Achondroplasia is a genetic disorder affecting
bone development
that results in short-limb dwarfism. Achondroplasia is the most common form of short-limb dwarfism, a disorder in which bone tissue does not develop properly, especially the long bones of the arms and legs.
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.
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.
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].
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.”
What chromosome is Turner syndrome found on?
The missing or altered
X chromosome
of Turner syndrome causes errors during fetal development and other developmental problems after birth — for example, short stature, ovarian insufficiency and heart defects.
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 |
|---|
Where is achondroplasia most common?
Achondroplasia is the most common type of short-limbed dwarfism. The condition occurs in
1 in 15,000 to 40,000 newborns worldwide
.
When is achondroplasia usually diagnosed?
Achondroplasia can be diagnosed
before birth by fetal ultrasound
. This test uses sound waves and a computer to create images of the baby growing in the womb. DNA testing can also be done before birth to confirm fetal ultrasound results. The condition can also be diagnosed after birth with a physical exam.
What is Noonan syndrome?
Noonan syndrome is
a genetic disorder that prevents normal development in various parts of the body
. A person can be affected by Noonan syndrome in a wide variety of ways. These include unusual facial characteristics, short stature, heart defects, other physical problems and possible developmental delays.
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.
