Fragile X syndrome (patient information): Difference between revisions
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==Overview== | ==Overview== | ||
Fragile X syndrome, also called Martin-Bell syndrome or Marker X syndrome, is a genetic condition involving changes in part of the X chromosome. It is the leading inherited cause of intellectual disorder and autism spectrum disorder with severe behavioral abnormalities . It is an X linked disorder, affecting both males and females. It is a genetic disease caused by CGG trinucleotide expansion (>200 CGG repeats). | [[Fragile X syndrome]], also called [[Martin-Bell syndrome]] or [[Marker X syndrome]], is a [[genetic]] condition involving changes in part of the [[X chromosome]]. It is the leading [[inherited]] cause of intellectual disorder and [[autism spectrum disorder]] with severe behavioral abnormalities . It is an [[X linked|X linked disorder]], affecting both males and females. It is a genetic disease caused by [[CGG trinucleotide repeat|CGG trinucleotide]] expansion (>200 CGG repeats). | ||
==What are the symptoms of Fragile X syndrome?== | ==What are the symptoms of Fragile X syndrome?== | ||
The physical features of Fragile X syndrome is prominent around the time of puberty. Physical features include: | The physical features of Fragile X syndrome is prominent around the time of [[puberty]]. Physical features include: | ||
*Large and protruding ears | *Large and protruding ears | ||
*Elongated face | *Elongated face | ||
*Macroorchidism (large testicles in men after puberty) | *[[Macroorchidism]] (large testicles in men after puberty) | ||
*Flat foot | *Flat foot | ||
*High Arched palate | *High Arched [[palate]] | ||
*Hyperflexible finger joints | *Hyperflexible finger joints | ||
*Low muscle tone | *Low [[muscle tone]] | ||
The common features in child with Fragile X Syndrome include low IQ with learning difficulties (intellectual disabilities). Behavioral abnormalities includes stereotypic movements (e.g., hand-flapping) hyperactivity, | The common features in child with Fragile X Syndrome include [[low IQ]] with [[learning difficulties]] (intellectual disabilities). Behavioral abnormalities includes [[stereotypic movements]] (e.g., hand-[[Flapping tremor|flapping]]) [[hyperactivity]], i[[Inattention|nattention]], poor [[social interaction]], limited [[eye contact]] and [[poor memory]]. Child with Fragile X syndrome often presents with [[developmental delay]] (including delayed attainment of [[Motor skill|motor]] and [[Language disorder|language]] [[milestones]]). Approximately, 20% of boy with Fragile X syndrome develops [[seizures]] (mostly simple or [[complex partial seizures]]) | ||
==What are the causes of Fragile X syndrome?== | ==What are the causes of Fragile X syndrome?== | ||
Fragile x Syndrome is a genetic disease which is caused by mutation in the Fragile x Mental Retardation 1(FMR1) gene in X chromosome. Generally, these mutation (>200 repeats of CGG) occurs at in the 5' untranslated region of FMR1.[3] In around 2% of cases, Fragile X syndrome can occur as a result of point mutation in FMR1 gene.[4] | [[Fragile X syndrome|Fragile]] x Syndrome is a genetic disease which is caused by mutation in the Fragile x Mental Retardation 1([[FMR1]]) [[gene]] in [[X chromosome]]. Generally, these [[Mutations|mutation]] (>200 repeats of CGG) occurs at in the 5' untranslated region of FMR1.[3] In around 2% of cases, Fragile X syndrome can occur as a result of [[Point mutations|point mutation]] in FMR1 gene.[4] | ||
Normally, the FMR1 gene makes a protein you need for your brain to grow properly. A defect in this gene makes your body produce too little of the protein, or none at all. | Normally, the FMR1 gene makes a protein you need for your [[brain]] to grow properly. A defect in this [[gene]] makes your body produce too little of the [[protein]], or none at all. | ||
Boys and girls can both be affected, but because boys have only one X chromosome, a single fragile X is likely to affect them more severely. You can have Fragile X syndrome even if your parents do not have it. | Boys and girls can both be affected, but because boys have only one [[X chromosome]], a single fragile X is likely to affect them more severely. You can have [[Fragile X syndrome]] even if your parents do not have it. | ||
==Who is at highest risk?== | ==Who is at highest risk?== | ||
There are no established risk factors for Fragile X syndrome. However, the child with family history of Fragile x Syndrome, autism disorder of unknown cause, developmental delay, adult onset ataxia/tremor or any intellectual disabilities are at greater risk of developing the disorder. | There are no established [[risk factors]] for Fragile X syndrome. However, the child with family history of Fragile x Syndrome, [[autism]] disorder of unknown cause, [[developmental delay]], adult onset ataxia/tremor or any [[Mental retardation|intellectual]] disabilities are at greater risk of developing the disorder. | ||
==How to know you have Fragile X syndrome?== | ==How to know you have Fragile X syndrome?== | ||
The diagnosis of Fragile X Syndrome is based upon detection of an alteration in the fragile X mental retardation 1 (FMR1) gene. | The [[diagnosis]] of [[Fragile X syndrome|Fragile X Syndrome]] is based upon detection of an alteration in the fragile X mental retardation 1 (FMR1) gene. | ||
Clinically, mentally retarded child with family history of Fragile X syndrome (especially a male relative) have higher chance of inheriting the disease. | Clinically, mentally retarded child with [[family history]] of Fragile X syndrome (especially a male relative) have higher chance of inheriting the disease. | ||
There are very few outward signs of Fragile X syndrome in babies. Babies may have a large head circumference. Measurement of oversized testes in males who have reached puberty may also suggest the diagnosis. An experienced geneticist may note subtle differences in facial characteristics. Mental retardation is the hallmark of this condition and, in females, this may be the only sign of the disease. A specific genetic test called polymerase chain reaction (PCR) is used to diagnose this disease. This test looks for an expanded mutation (called a triplet | There are very few outward signs of Fragile X syndrome in babies. Babies may have a large head circumference. Measurement of oversized [[testes]] in males who have reached [[puberty]] may also suggest the diagnosis. An experienced geneticist may note subtle differences in facial characteristics. [[Mental retardation]] is the [[hallmark]] of this condition and, in females, this may be the only sign of the disease. A specific genetic test called [[polymerase chain reaction]] (PCR) is used to diagnose this disease. This test looks for an expanded mutation (called a [[Trinucleotide repeat disorder|triplet repea]]<nowiki/>t) in the FMR1 gene. | ||
==When to seek urgent medical care== | ==When to seek urgent medical care== | ||
Call your health care provider if you suspect the possibility of Fragile X syndrome in a child with mental retardation. | Call your health care provider if you suspect the possibility of Fragile X syndrome in a child with [[mental retardation]]. | ||
==Treatment options== | ==Treatment options== | ||
There is no specific treatment for Fragile X syndrome. There are some medication under trial such as fenobam (mGLUR5 antagonist) and Lithium (mGLUR5 signaling inhibitor). Effort is directed toward training and education so that affected children can function at as high a level as is possible. Because the condition is not rare, specific educational approaches have been developed and tested. | There is no specific [[treatment]] for Fragile X syndrome. There are some [[medication]] under trial such as [[fenobam]] (mGLUR5 antagonist) and [[Lithium]] (mGLUR5 signaling inhibitor). Effort is directed toward training and education so that affected children can function at as high a level as is possible. Because the condition is not rare, specific educational approaches have been developed and tested. | ||
==Diseases with similar symptoms== | ==Diseases with similar symptoms== | ||
*[[Down syndrome]] | *[[Down syndrome]] | ||
Fragile X syndrome must be differentiated from [[Autism]] Spectrum Disorder, [[Attention deficit hyperactivity disorder]] (ADHD), Fragile XE syndrome ([[FRAXE]]), [[Klinefelter's syndrome|Klinefelter]] syndrome and [[Prader-Willi syndrome|Prader-Willi]] syndrome (PWS). | |||
==Where to find medical care for Fragile X syndrome== | ==Where to find medical care for Fragile X syndrome== | ||
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==Prevention of Fragile X syndrome== | ==Prevention of Fragile X syndrome== | ||
Genetic counseling and prenatal screening is recommended when one of the parents is shown to be a carrier of fragile X. Prenatal testing can be done by amniocentesis at 16-20 weeks or by chorionic villus sampling (CVS) at 10-13 weeks to determine if a fetus has inherited the fragile X gene | [[Genetic counseling]] and [[Prenatal diagnosis|prenatal screening]] is recommended when one of the parents is shown to be a carrier of fragile X. Prenatal testing can be done by [[amniocentesis]] at 16-20 weeks or by [[chorionic villus sampling]] (CVS) at 10-13 weeks to determine if a fetus has inherited the fragile X gene | ||
==What to expect (Outlook/Prognosis)== | ==What to expect (Outlook/Prognosis)== | ||
The outcome depends on the extent of mental retardation. Life expectancy is normal. | The outcome depends on the extent of mental retardation. [[Life expectancy]] is normal. | ||
== | ==What are the possible complications?== | ||
Complications in Fragile X syndrome patient may include scoliosis or mitral valve prolapse (most frequently encountered cardiac defect). | Complications in Fragile X syndrome patient may include [[scoliosis]] or [[mitral valve prolapse]] (most frequently encountered [[cardiac]] [[defect]]). | ||
==Sources== | ==Sources== | ||
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{{WH}} | {{WH}} | ||
{{WS}} | {{WS}} | ||
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Latest revision as of 07:47, 3 September 2021
For the WikiDoc page for this topic, click here
| Fragile X syndrome (patient information) | |
 | |
|---|---|
| Location of FMR1 gene | |
| ICD-10 | Q99.2 |
| ICD-9 | 759.83 |
| OMIM | 309550 |
| DiseasesDB | 4973 |
|
Fragile X syndrome |
|
Fragile X syndrome On the Web |
|---|
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Assistant Editor-in-Chief: Alexandra M. Palmer
Overview
Fragile X syndrome, also called Martin-Bell syndrome or Marker X syndrome, is a genetic condition involving changes in part of the X chromosome. It is the leading inherited cause of intellectual disorder and autism spectrum disorder with severe behavioral abnormalities . It is an X linked disorder, affecting both males and females. It is a genetic disease caused by CGG trinucleotide expansion (>200 CGG repeats).
What are the symptoms of Fragile X syndrome?
The physical features of Fragile X syndrome is prominent around the time of puberty. Physical features include:
- Large and protruding ears
- Elongated face
- Macroorchidism (large testicles in men after puberty)
- Flat foot
- High Arched palate
- Hyperflexible finger joints
- Low muscle tone
The common features in child with Fragile X Syndrome include low IQ with learning difficulties (intellectual disabilities). Behavioral abnormalities includes stereotypic movements (e.g., hand-flapping) hyperactivity, inattention, poor social interaction, limited eye contact and poor memory. Child with Fragile X syndrome often presents with developmental delay (including delayed attainment of motor and language milestones). Approximately, 20% of boy with Fragile X syndrome develops seizures (mostly simple or complex partial seizures)
What are the causes of Fragile X syndrome?
Fragile x Syndrome is a genetic disease which is caused by mutation in the Fragile x Mental Retardation 1(FMR1) gene in X chromosome. Generally, these mutation (>200 repeats of CGG) occurs at in the 5' untranslated region of FMR1.[3] In around 2% of cases, Fragile X syndrome can occur as a result of point mutation in FMR1 gene.[4]
Normally, the FMR1 gene makes a protein you need for your brain to grow properly. A defect in this gene makes your body produce too little of the protein, or none at all.
Boys and girls can both be affected, but because boys have only one X chromosome, a single fragile X is likely to affect them more severely. You can have Fragile X syndrome even if your parents do not have it.
Who is at highest risk?
There are no established risk factors for Fragile X syndrome. However, the child with family history of Fragile x Syndrome, autism disorder of unknown cause, developmental delay, adult onset ataxia/tremor or any intellectual disabilities are at greater risk of developing the disorder.
How to know you have Fragile X syndrome?
The diagnosis of Fragile X Syndrome is based upon detection of an alteration in the fragile X mental retardation 1 (FMR1) gene. Clinically, mentally retarded child with family history of Fragile X syndrome (especially a male relative) have higher chance of inheriting the disease. There are very few outward signs of Fragile X syndrome in babies. Babies may have a large head circumference. Measurement of oversized testes in males who have reached puberty may also suggest the diagnosis. An experienced geneticist may note subtle differences in facial characteristics. Mental retardation is the hallmark of this condition and, in females, this may be the only sign of the disease. A specific genetic test called polymerase chain reaction (PCR) is used to diagnose this disease. This test looks for an expanded mutation (called a triplet repeat) in the FMR1 gene.
When to seek urgent medical care
Call your health care provider if you suspect the possibility of Fragile X syndrome in a child with mental retardation.
Treatment options
There is no specific treatment for Fragile X syndrome. There are some medication under trial such as fenobam (mGLUR5 antagonist) and Lithium (mGLUR5 signaling inhibitor). Effort is directed toward training and education so that affected children can function at as high a level as is possible. Because the condition is not rare, specific educational approaches have been developed and tested.
Diseases with similar symptoms
Fragile X syndrome must be differentiated from Autism Spectrum Disorder, Attention deficit hyperactivity disorder (ADHD), Fragile XE syndrome (FRAXE), Klinefelter syndrome and Prader-Willi syndrome (PWS).
Where to find medical care for Fragile X syndrome
Directions to Hospitals Treating Fragile X syndrome
Prevention of Fragile X syndrome
Genetic counseling and prenatal screening is recommended when one of the parents is shown to be a carrier of fragile X. Prenatal testing can be done by amniocentesis at 16-20 weeks or by chorionic villus sampling (CVS) at 10-13 weeks to determine if a fetus has inherited the fragile X gene
What to expect (Outlook/Prognosis)
The outcome depends on the extent of mental retardation. Life expectancy is normal.
What are the possible complications?
Complications in Fragile X syndrome patient may include scoliosis or mitral valve prolapse (most frequently encountered cardiac defect).