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FAQ - Achondroplasia
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can normal parents have a child with achondroplasia?.?
can normal parents have a child with achondroplasia?.
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According to Wikipedia - yes they can. A mutation in the father's sperm can cause it - even if the father does not have it. (+ info)
Achondroplasia Dwarfism?
Achondroplasia (dwarfism)
a) What is the genotype of this disorder
b) What is happening with the DNA to cause these phenotypic effects?
c) What are the phenotypic effects of this disorder?
d) How is this disorder inherited?
e) Are there carrier forms and/or lethal forms of this disorder?
f) How can this disorder be treated?
g) How can this disorder be avoided?
Any help would be awesome! Thanks!
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This should help you out:
http://www.google.com/search?q=Achondroplasia&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a (+ info)
how long do people who have achondroplasia live ?
Achondroplasia is a genetic disorder of bone growth that is evident at birth. It affects about one in every 25,000 births and it occurs in all races and in both sexes. Its depiction in ancient Egyptian art makes it one of the oldest recorded birth defects.
The vast majority of individuals with achondroplasia have normal intelligence and lead healthy, independent, and productive lives (Rogers et al, 1979). Rarely, intelligence may be affected secondary to hydrocephalus or other CNS complications.
Mean adult height is approximately 131 cm + 5.6 for males and 124 cm + 5.9 for females. Presence of severe disproportionate short stature can cause a number of psychosocial problems.
Life span for heterozygous achondroplasia is usually normal unless there are serious complications. A mean life expectancy is approximately 10 years less than the general population (Hecht et al, 1987).
Homozygous achondroplasia is a lethal condition with severe respiratory distress caused by rib-cage deformity. Radiographic changes are much more severe than the heterozygous achondroplasia. The patients die soon after birth. (+ info)
who/what is achondroplasia named for?
im doing a scienceee report on achondroplasia its a rare disorder or somthing lol soo if you knoo the above question or what it means plzzz lemme know cuz im confusedd lol thx<333
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Achondroplasia dwarfism is a type of autosomal dominant genetic disorder that is a common cause of dwarfism. Achondroplastic dwarfs have short stature, with an average adult height of 131 cm (4 feet, 3.8 inches) for males and 123 cm (4 feet, 0.6 inches) for females.
The prevalence is approximately 1 in 25,000.
Epidemiology
Achondroplasia is one of several congenital conditions with similar presentations, such as osteogenesis imperfecta, multiple epiphyseal dysplasia tarda, achondrogenesis, osteopetrosis, and thanatophoric dysplasia. This makes estimates of prevalence difficult, with changing and subjective diagnostic criteria over time. One detailed and long-running study in the Netherlands found that the prevalence determined at birth was only 1.3 per 100,000 live births[2]. However, another study at the same time found a rate of 1 per 10,000[2].
[edit] Causes
Achondroplasia is a result of an autosomal dominant mutation in the fibroblast growth factor receptor gene 3 (FGFR3), which causes an abnormality of cartilage formation. FGFR3 normally has a negative regulatory effect on bone growth. In achondroplasia, the mutated form of the receptor is constitutively active and this leads to severely shortened bones.
Animals with achondroplasia have one normal copy of the fibroblast growth factor receptor 3 gene and one mutant copy. Two copies of the mutant gene are invariably fatal before, or shortly after birth. Only one copy of the gene needs to be present for the disorder to occur. Therefore, a person with achondroplasia has a 50% chance of passing on the gene to their offspring, meaning that there will be a 50% chance that each child will have achondroplasia. Since two copies (Homozygous) are fatal, if two people with achondroplasia have a child, there is a 25% chance of the child dying shortly after birth, a 50% chance the child will have achondroplasia, and a 25% chance the child will have a normal phenotype. However, in the majority of cases, people with achondroplasia are born to parents who don't have the condition. This is the result of a new mutation.[3]
New gene mutations are associated with increasing paternal age[4] (over 35 years). Studies have demonstrated that new gene mutations are exclusively inherited from the father and occur during spermatogenesis (as opposed to resulting from a gonadal mosaicism). More than 99% of achondroplasia is caused by two different mutations in the fibroblast growth factor receptor 3 (FGFR3). In about 98% of cases, a G to A point mutation at nucleotide 1138 of the FGFR3 gene causes a glycine to arginine substitution (Bellus et al 1995, Shiang et al 1994, Rousseau et al 1996). About 1% of cases are caused by a G to C point mutation at nucleotide 1138.
There are two other syndromes with a genetic basis similar to achondroplasia: hypochondroplasia and thanatophoric dysplasia. (+ info)
What is Achondroplasia?
im doing a project and my baby has this desease can you help me and let me know wut it is?
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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). (+ info)
has anybody heard of a genetic disorder called achondroplasia?
achondroplasia - Improper development of cartilage at the ends of the long bones, resulting in a form of congenital dwarfism. (+ info)
What diseases can develope from a tumor in the parathyroid gland?
From the list below.
1. Osteoarthritis
2. Achondroplasia
3. Osteoporosis
4. Hypocalcemia
5. Hyperthyroidism
6. Hypercalcemia
Please explain.
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Parathyroid is a gland in neck whih produces a hormone called PTH (parathyroid hormone). Its oversecretion will cause:
Hypercalcemia
PTH causes increase absorption of calicium from Gut/ kidney and bone and increased excretion of phosphate from kidney thus it will lead to Hypercalcemia (increased caliun level in blood) and hypophosphatemia.
Most common cause of hyperparathyroidism is adenoma (85%) (+ info)
what kind of mutation is achondroplasia?
e.g. point mutation, deletion, chromosomal aberratrions, etc.
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The source below says that it is generally caused by a point mutation in the FGFR3 gene. (+ info)
Five interesting facts about Achondroplasia?
(+ info)
how does achondroplasia [[dwarfism]] affect everyday life? i have a project, but i cant seem to find it.?
I am a Achon dwarf.... I find the main things that affect everyday life are the heights of things such as stove tops, benches, and supermarket shelving. At the moment in our stores, a lot of clothes are 3/4 length in the sleeves and pants which is extremely beneficial to my clothes buying otherwise I must get my clothes altered.
Shoes can be a problem, my feet are a bit small but also a bit wide, so in sneakers and sandals I often buy boys as they are usually wider and come in great colours!
Something else that can affect everyday life if I let it is the attitude of others... especially when parents of children ignore their child's questions about me... usually they just want to confirm that they have seen a little person...all they need is a "yes dear that person is little". But overall people mean well, and I appreciate that. (+ info)