What is Achondroplasia?

Question

im doing a project and my baby has this desease can you help me and let me know wut it is?

Answer 1

Greenberg Center for Skeletal Dysplasias
Achondroplasia

Achondroplasia is the most common form of short-limb dwarfism. It occurs in approximately 1 in 26,000 to 1 in 40,000 births. The characteristic features of achondroplasia are apparent at birth. These include typical facial features, disproportionate short stature, and rhizomelic (the proximal ends of the limbs) shortening. Diagnosis of achondroplasia is made by physical exam and skeletal x-rays. Most individuals have normal intelligence. Infants and children often have motor delays but cognitive delays are not present. A special infant developmental chart has been made for children with achondroplasia. Final adult height is in the range of 4 feet. Special achondroplasia growth curves have also been made. These should be used by the child's pediatrician to monitor growth and development.

The facial features include a large head with a prominent forehead. The midface is often small with a flat nasal bridge and narrow nasal passages. In infancy and childhood, middle ear infections often occur because of the small nasal passages and Eustachian tube dysfunction. If the ear infections are left untreated, hearing loss can occur. "Ear tubes" are probably indicated for a child with multiple ear infections. The jaw appears to be prominent. Occasionally dental crowding can occur since the jaw is small.

Respiratory problems can occur in infants and children. Airway obstruction can be "central" in origin (due to foramen magnum compression) or "obstructive" in origin (due to narrowed nasal passages). Symptoms of airway obstruction include snoring, sleeping with the neck in a hyperextended position, or apnea. A sleep study is done if these symptoms exist to determine the cause of the airway obstruction. Treatment depends on the type of obstruction. I f central obstruction is present, a foramen magnum decompression is performed (see below). If obstructive airway obstruction is present, therapy can include tonsillectomy, adenoidectomy, or tracheostomy placement.

The limbs have rhizomelic shortening. The legs are straight in infancy but when a child starts walking, they can develop a valgus (knock-knee) position. As the child continues to walk, the legs assume a varus (bowleg) appearance. Occasionally, children have these leg curvatures corrected. The fingers and toes are short. Infants have a thoracolumbar kyphosis in the sitting position. Since infants with achondroplasia often have reduced tone, it is recommended that they not be placed in umbrella-type strollers, jumpers, or swings that do not provide good back support since these devices may lead to the development of a gibbus or hump in the back. As the child begins to walk, the kyphosis disappears and the back assumes a lordotic posture. If a child is delayed in walking, the spine should be monitored closely for signs of gibbus formation.

Neurologic complications can occur in achondroplasia. In infancy, hydrocephalus can develop. Infants should be monitored monthly with measurements of their head circumference to detest a rapidly enlarging head size that can indicate hydrocephalus. The child's pediatrician should have a copy of the head circumference curves for children with achondroplasia. Radiologic studies are indicated if the head circumference increases disproportionately or if symptoms of hydrocephalus develop. Common radiologic procedures include head ultrasound, CT scan, or MRI of the head. If intervention is necessary, a ventriculoperitoneal (VP)-shunt is placed to relieve the excess pressure. Infants should also be monitored for foramen magnum compression. The foramen magnum is the opening at the base of the skull through which the brainstem and cervical spinal cord exit. Individuals with achondroplasia have narrowed foramen magnums that can then compress the brain stem and spinal cord. Symptoms of narrowing include apnea (cessation of breathing) and cervical myelopathy. CT-scans and MRI scans are done to examine the size of the foramen magnum. If a child is having symptoms, a neurosurgical procedure called foramen magnum decompression is done to enlarge the foramen magnum and alleviate further symptoms. Adolescents and adults are at risk of developing lumbosacral spinal stenosis. The lumbar spinal cord or nerve roots become compressed producing neurologic symptoms. Initial symptoms include weakness, tingling, and pain of the legs. Often the pain is alleviated by assuming a squatting position. As the condition worsens, pain in the low back or buttocks occurs. Diagnosis is made by a neurologic exam, SERs (somatic evoked responses), and CT or MRI scans. Treatment is a neurosurgical procedure called a lumbar laminectomy.

Achondroplasia is an autosomal dominant condition (see the genetics section for further details). This means that a person with achondroplasia has a 1 in 2 or 50% chance of having children with achondroplasia. However, approximately 75% of individuals with achondroplasia are born to parents of average size. In these cases, achondroplasia is due to a new mutation or genetic change. The gene for achondroplasia has been found. It is called fibroblast growth factor receptor 3 (FGFR3). Often, two individuals with achondroplasia have children. These couples are at risk of having a child with 2 copies of the changed gene or double homozygosity. Infants with homozygous achondroplasia are either stillborn or die shortly after birth. Couples at risk often have prenatal diagnosis via serial ultrasounds. A DNA test is now also available to detect double homozygosity.
References

1. Hall, JG. Health supervision for children with achondroplasia. Pediatrics1995; 95:443-451.
2. Hunter, AGW, et. al. Standard curves of chest circumference in achondroplasia and the relationship of chest circumference to respiratory problems. Am J Med Genet 1996; 62:91-97.
3. Hunter, AGW, et. al. Standard weight for height curves in achondroplasia. Am J Med Genet 1996; 62:255-261.

For more detailed information, see Online Mendelian Inheritance in Man (OMIM).

Answer 2

I use www.emedicine.com to look up medical information, below is some description of what it is and what it means, but go to the website for more detail information, it has about 11 section of achondroplasia. very detailed.

Background: Achondroplasia is a common, nonlethal form of chondrodysplasia. It is transmitted as an autosomal dominant trait with complete penetrance. De novo mutations cause 75-80% of cases. The mutation rate is estimated to be 0.000014 per gamete per generation. Cardinal features include short stature, rhizomelic shortening of the arms and legs, a disproportionately long trunk, trident hands, midfacial hypoplasia, prominent forehead (frontal bossing), thoracolumbar gibbus, true megalencephaly, and caudal narrowing of the interpedicular spaces.

Pathophysiology: Achondroplasia is caused by mutations in the gene for fibroblast growth factor receptor-3 (FGFR3). The gene has been mapped to band 4p16.3. The common mutations cause a gain of function of the FGFR3 gene, resulting in decreased endochondral ossification, inhibited proliferation of chondrocytes in growth plate cartilage, decreased cellular hypertrophy, and decreased cartilage matrix production. G1138A and G1138C mutations account for approximately 99% of the mutations resulting in a specific amino acid substitution (G380R). A rare mutation is the novel missense mutation (Lys650Met) in the tyrosine kinase region, which results in a disorder termed severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN). Another mutation, Gly380Arg, has been reported in a Spanish population.

Answer 3

a) The situation is prompted via a brand new mutation within the fibroblast progress element receptor three (FGFR3) gene. This gene is assumed to be dependable for achondroplasia dwarfism; nonetheless, scientists have no idea why this mutation happens. c)Characteristic signs of achondroplasia dwarfism comprise: * An usual-measurement trunk. * Short legs and arms, with peculiarly brief higher fingers and thighs. * An enlarged head (macrocephaly) with a distinguished brow . * Fingers which can be often brief. The ring finger and center finger would possibly diverge, giving the hand a 3-pronged (trident) look. d) Achondroplasia dwarfism may also be inherited in an autosomal dominant sample, because of this that one replica of the altered gene in each and every cellphone is enough to intent the disease. In those instances, probably the most mum and dad with achondroplasia dwarfism passes at the FGFR3 gene to the youngster. f, g )Although there are not any achondroplasia cures with a purpose to treatment achondroplasia, there are cures that contain stopping or treating the indicators, signs or wellness stipulations that arise consequently of achondroplasia. Achondroplasia cures additionally awareness on social and loved ones help.

Answer 4

Achondroplasia is characterized by abnormal bone growth that results in short stature with disproportionately short arms and legs, a large head, and characteristic facial features with frontal bossing and mid-face hypoplasia. In infancy, hypotonia is typical, and acquisition of developmental motor milestones is often delayed. Intelligence and life span are usually normal, although compression of the spinal cord and/or upper airway obstruction increases the risk of death in infancy.
Recommendations for management of children with achondroplasia include monitoring of height, weight, and head circumference; measures to avoid obesity; MRI or CT for evaluation of severe hypotonia or signs of spinal cord compression; adenotonsillectomy, continuous positive airway pressure (CPAP) by nasal mask, and tracheostomy to correct obstructive sleep apnea; suboccipital decompression as indicated for lower-limb hyperreflexia or clonus and central hypopnea; surgery

Answer 5

Have you seen ( little people, big world ) on TLC?
they are normal people but they have short limbs (short legs & short arms)
you better see this show on TLC, very nice & very very encourging.
tis is a link to the show
http://tlc.discovery.com/fansites/lpbw/lpbw.html

& this is a link to the disease itself
http://www.emedicine.com/ped/topic12.htm

Answer 6

It is a genetic disorder where the growth of trunk remains normal, while extremities --arms and legs-- are short,due to failure of development of long bones(known as achondrogenesis)
please refer to the site--- http://www.medicinenet.com/achondroplasia/article.htm