Fragile X syndrome, also termed Martin-Bell syndrome or marker X syndrome, is the most common cause of inherited mental retardation. Fragile X syndrome has been found in all major ethnic groups and races, and is caused by an abnormality (mutation) in the FMR1 gene. FMR1 is a gene located . Fragile X syndrome is caused by the expansion or lengthening of the FMR1 gene on the X chromosome, known as a gene mutation. The X chromosome is one.
|Published (Last):||7 March 2018|
|PDF File Size:||15.27 Mb|
|ePub File Size:||19.53 Mb|
|Price:||Free* [*Free Regsitration Required]|
Fragile X Syndrome: MedlinePlus
Alexithymia Attention deficit hyperactivity disorder Anxiety disorder obsessive—compulsive disorder Late talker Epilepsy Fragile X syndrome Hyperlexia Savant syndrome Sensory processing disorder Intellectual disability Developmental coordination disorder Multiple complex developmental disorder. Insights from model systems”.
Some drugs, originally developed to treat other disorders, were shown to be effective in treating symptoms of fragile X syndrome in the animal models but when used on human subjects appeared to be less effective.
There is no cure. The subsequent abnormalities in the formation and function of synapses and development of neural circuits result in impaired neuroplasticityan integral part of memory and learning. From their 40s onward, males with FXS begin developing progressively more severe problems in performing tasks that require the central executive of working memory.
For a detailed discussion of Treatments and Interventions please go to the National Fragile X Foundation website https: Intragenic FMR1 disease-causing variants: Current trends in treating the disorder include medications for symptom-based treatments that aim to minimize the secondary characteristics associated with the disorder.
Am J Ment Defic. New situations may cause a child with Fragile X syndrome to become severely anxious or afraid. Handbook of neurodevelopmental and genetic disorders in children.
Curr Neurol Neurosci Rep. Very rarely females will present with this syndrome.
Pervasive developmental disorders and autism spectrum F84 InJames Purdon Martin and Julia Bell described a pedigree of X-linked mental disability, without considering the macroorchidism larger testicles. Typically, onset of tremor occurs in the sixth decade of life, with subsequent progression to ataxia loss of coordination and gradual cognitive decline. The physical features in affected males are variable and may not be obvious until puberty. Premutations have CGG repeats and are potentially unstable.
FXS is characterized by social anxietyincluding poor eye contact, gaze aversion, prolonged time to commence social interaction, and challenges forming peer fraji. Alzheimer’s disease Huntington’s disease Creutzfeldt—Jakob disease chaperonins: Fragile X syndrome has traditionally been considered an X-linked dominant condition with variable expressivity and possibly reduced penetrance.
The Cochrane Database of Systematic Reviews 5: Current pharmacological treatment centers on managing problem behaviors and psychiatric symptoms associated with FXS. The greater the number of copies of CGG in a fraajil, the more likely these will increase to become a full mutation causing the fragile X syndrome in offspring. Standard Therapies Treatment There are many treatments for fragile X syndrome that can improve the lives of affected individuals and their families.
The Johns Hopkins University. Because the premutation is relatively stable when transmitted from father to daughter, the daughters fraiil never are affected with fragile X syndrome. Comparisons may be useful for a differential diagnosis:. General Discussion Fragile X syndrome is characterized by moderate intellectual disability in affected males and mild intellectual disability in affected females.
What causes Fragile X Syndrome
Other symptoms can include flat feet, frequent ear infections, low muscle frajjil, a long narrow face, high arched palate, dental problems, crossed eyes strabismus and heart problems including mitral valve prolapse. Fragile X syndrome Orphanet: Therapeutics development for triplet repeat expansion diseases. Comparisons may be useful for a differential diagnosis: It is also the most common single gene cause of autism worldwide.
Motor and language delays are usually present but also become more apparent over time. This requires early identification to avoid amblyopia.
The fragile X premutation: However, about four times as many females appear to be carriers of the altered gene as do males 1: These children have difficulty in large crowds due to the loud noises and this d lead to tantrums due to hyperarousal. This test can detect carriers and fully affected individuals.
In contrast, female offspring whose fathers have a premutation always inherit it and thus grandchildren of males with the premutation are at risk to have fragile X syndrome. Eur J Hum Genet ; The development of animal models for fragile Fraijl syndrome studies over the last two decades resulted in great anticipation that effective drug treatments could be discovered.
Fragile X syndrome FXS is a genetic disorder. A genetic blood test can diagnose Fragile X. The fragile X syndrome affects about 1 in 4, males and 1 in 6, to 8, females in the USA; that is, it affects about twice frqjil many males as it does females.
Drugs of the Future. In the meantime, appropriate education and therapies may help and medications are available that target symptoms. However, their children are at increased risk because the premutation may be unstable when transmitted to the next generation.
Initial signs of the disorder may include difficulty writing, using utensils, pouring and walking. Normally, the X chromosome contains between 6 and 50 repeats of a gene the FMR1 gene responsible for producing a protein vital for normal brain development.
For You Women Patient Handouts. Since the s, more sensitive molecular techniques have been used to determine carrier status. Getting treatment early can help.