Our bodies are made up of millions of cells. Each cell contains thousands of genes. Genes are like a set of instructions, controlling our growth and how our bodies work. Genes are responsible for many of our characteristics such as our eye colour, blood type or height. Any alteration in a gene can stop a gene working properly.
Genes are carried on thread like structures called chromosomes. Chromosomes are arranged in 23 pairs, according to size. We normally inherit one of each of the pairs from our mother and one from our father. Twenty two of these are the same in both sexes. The twenty third pair are the sex chromosomes. Women have two X chromosomes (XX) and men have an X and a Y chromosome (XY).
The gene that causes FXS lies near the tip of the X chromosome. Under a microscope, the tip looks like it has broken off but not quite separated. This is how the disorder got its name.
At the beginning of the normal fragile X gene a small part of the genetic code is repeated several times. In people with FXS the repeated part of the gene is larger than normal (they have more repeats). This is called an expansion, because part of the gene has grown bigger or expanded. If it grows too big it interferes with the normal instructions and causes fragile X.
Experimental drug to treat fragile X syndrome
The drug is still in an early stage of development, but its success gives researchers courage to move on to larger trials that may lead to a filing for approval with the Food and Drug Administration.
The drug holds promise for the future treatment of fragile X syndrome, the most common form of inherited intellectual disability in boys, said Robert T. Schultz, Director of the Center for Autism Research at the Children's Hospital of Philadelphia.
Fox News
Retired teacher active with Fragile X Foundation
Age: 61
Residence: Highland Beach
Family: Husband, Michael; two sons
Career: Retired teacher
Cause: The National Fragile X Foundation, an organization formed in 1984 to help families, spread awareness and support research for all Fragile X-associated disorders.
Q: Why do you volunteer?
A: I was the mother of a son who had something wrong with him, but no one could say what. Before Dan became diagnosed with Fragile X at 21, I had to go it alone without much help. I volunteer so other people don't go through what I did.
A: NAXF is the largest and strongest group lobbying to support research in Fragile X. They also offer support and information to people concerning Fragile X-associated disorders. It's where I can make the greatest difference in helping others.
Q: Describe your volunteer role.
A: I am a volunteer at Dan's weekly bowling league in Boca Raton. For the Special Olympics, I volunteer at the adult bowling group. Through NAXF, once a year I go toWashington, D.C., to lobby for continued federal research funding. On July 25-29, the Fragile X conference will be in Miami, and I am co-chair for recruiting volunteers. And I advocate for all special-needs adults.
Q: What are your goals?
A: My short-term goal is to recruit 50 volunteers for the NAFX convention. My ongoing goal is to spread the word about Fragile X syndrome so that more of the population gets tested. When Dan was born 34 years ago, no accurate blood tests existed; today they do. This means families should be tested. My grandmother, mother, aunt and I were all silent carriers.
Q: What challenges do you face?
A: Dan doesn't have the ability to live on his own yet. He is very good in a routine, but not in handling change or in always reacting appropriately. Right now, he still needs an advocate in his corner. But he continues to grow and his abilities continue to increase, so I'm optimistic.
Q: What has Dan accomplished?
A: Since he was 17, Dan has worked at McDonald's, first in Chicago and now in Boca. He tried several jobs initially, but he loved McDonald's. Actually, he's so well trained he can work at any McDonald's in the world. The supervisor in Boca said, "I thought I'd give him a chance, but I never expected him to be so good."
Q: What have you personally accomplished?
A: I've just reissued as an eBook "The Broken Toy: A Story of a Fragile X Syndrome Child." It's to help parents of special-needs children, starting from childhood and going into adulthood. [Visit] http://www.brokentoybook.com.
Q: What does your organization need?
A: Increased awareness of Fragile X and the progress being made to find a cure.
For more information, please visit http://www.fragilex.org.
Frequently Asked Questions
Did I do anything to cause fragile X syndrome?No. There is nothing you did before or during the pregnancy or after your child was born to cause fragile X syndrome. Fragile X syndrome is genetic which means it is caused by a change in a gene, in this case, the FMR1 gene. The change causes the gene not to work the way it should, leading to the problems seen in fragile X syndrome.
Because fragile X syndrome is genetic, it can be passed on and you are at risk for having another child with fragile X syndrome. It is important to know that you have no control over whether this change gets passed on to your child or not. In addition, other family members may also be at risk of having children with fragile X syndrome, so it is important to inform them of your child's diagnosis.
What does cause fragile X syndrome?
Explaining how fragile X happens is not very easy simply because of the way it is inherited. To start, let's talk broadly about genes and chromosomes. Genes are the instructions that tell our bodies how to work and are made up of DNA. We inherit two copies of all of our genes: one copy from our mother and one copy from our father. The DNA is packed into larger structures called chromosomes, and each chromosome contains hundreds to thousands of genes. Most people have 23 pairs of chromosomes, for a total of 46 chromosomes. The first 22 pairs are the same in males and females and are called the autosomes. The 23rd pair, called the sex chromosomes, are different in males and females. Females have two "X" chromosomes, and males have one "X" and one "Y" chromosome.
Fragile X is caused by a change in the FMR1 gene on the X chromosome that causes it not to work properly. Everyone has 6-10 genes that don't work the way they should, but this generally does not cause a problem. However, the change in the FMR1 gene does make a difference. This change (also called a mutation) in the FMR1 gene is complex and occurs over many generations.
The FMR1 gene contains a section of repetitive DNA that in most of the population is only 10-40 repeats long. In those with fragile X syndrome, this repeated region has expanded to over 200 repeats. When a repeat length is greater than 200, it is referred to as a full mutation or expansion. At this size, the FMR1 gene cannot function and the FMR1 protein cannot be produced. It is the inability of cells to make this protein that is responsible for fragile X syndrome.
In general, every person gets two copies of every gene. This is a little bit different for the FMR1 gene because it is on the "X" chromosome. Because males have only one "X" chromosome, they have only one copy of the FMR1 gene. If they have a full mutation, their one copy of the FMR1 gene is not working, and one sees the signs of fragile X syndrome. Because females have two "X" chromosomes and 2 copies of the FMR1 gene, if a girl inherits a full mutation, the other copy of the gene is usually working, so girls with a full mutation are still able to make FMR1 protein. This is why girls usually have fewer signs of fragile X than boys do.
In general, we expect to see the full mutation in every cell of a person with fragile X syndrome. Sometimes, however, an individual with fragile X syndrome can have what is called mosaicism. There are two kinds of mosaicism in fragile X syndrome: repeat size mosaicism and methylation mosaicism. In repeat size mosaicism, an individual has some cells that have a full mutation and some cells that have a premutation. In methylation mosaicism, all the cells have a full mutation, but the methylation pattern may not be the same in all cells. Some research studies have shown that individuals with repeat size or methylation mosaicism may be less affected than those who do not have mosaicism.
What is methylation?
Methylation is a process in which a chemical group, called a methyl group, gets added to the DNA. When enough methyl groups are added to the DNA, the gene gets turned off. When methyl groups are removed, the gene gets turned on. This is a normal process and many of our genes are controlled by methylation. However, in fragile X syndrome, the methylation of the FMR1 gene turns the gene off when it should be turned on. When FMR1 is turned off, its protein is not made, and you see the features of fragile X syndrome.
When someone with fragile X syndrome has methylation mosaicism, not all cells will have the FMR1 gene turned off by methylation. Some cells may have it partially turned off, and some cells may have the FMR1 gene turned on.
I heard only boys have fragile X syndrome. Why does my daughter have it also?
Girls can also have fragile X syndrome even though they have two "X" chromosomes. The reason is that they have a full expansion on one chromosome and a normal repeat section (in most cases) on the other chromosome. The copy with the full expansion is not making any FMR1 protein, while the other copy (the normal repeat section) is making protein. Although some protein is being made, it may not be enough, so we can see characteristics of fragile X syndrome. However, because some protein is being made, girls with fragile X syndrome are generally less affected than boys.
Is there a cure?
At this time, there is no cure for fragile X syndrome. Treatment for fragile X syndrome is provided through therapies such as special education, speech and language therapy, and occupational therapy. Medications may be helpful in managing hyperactivity, short attention span, and other behavioral or emotional problems. In order to determine the best course of action for your child, a comprehensive evaluation is recommended.
Source: www.childrenshospital.org
Fragile X Syndrome Facebook
There is very nice application at Facebook social media site. if you want you can add this application to your facebook profile for more information. Go to there:
Fragile X Syndrome & Autism
Fragile X Syndrome & Autism
what is pre-mutation ?
what is PCR/Polymerase chain reaction ?
PCR/Polymerase chain reaction: A method to increase or amplify specific sequences of DNA. This method can be used to detect the presence of changes in DNA sequence that can be the cause of genetic disorders.
what is FMR1 ?
FMR1: A gene on the X chromosome that encodes instructions for building the Fragile X Mental Retardation Protein (FMRP). A mutation in this gene causes the Fragile X syndrome.
what is CGG repeat ?
fragile x syndrome glossary
Adenine: One of the four bases that make up DNA. Abbreviated with an 'A'.
Carrier: A person that carries a gene that causes a disorder, but does not show symptoms.
Chromosome: Chromosomes are packages of DNA found in the nucleus of cells. Humans have 46 chromosomes.
Cytosine: One of the four bases that make up DNA. Abbreviated with a 'C'.
DNA: Short for deoxyribonucleic acid, DNA is the molecule that carries genetic information.
Full mutation: A mutation in the FMR1 gene with 200 or more CGG repeats.
FMRP: A protein involved in the maturation of neurons in the brain. People with Fragile X lack this protein.
Gene: A portion of DNA that contains instructions for making a protein.
Genotype: The genetic composition of a person. Usually used when considering one gene or chromosome (eg males have a XY genotype, females have a XX).
Guanine: One of the four bases that make up DNA. Abbreviated with a 'G'.
Methyl group: A small molecule that turns off the FMR1 gene in people with Fragile X.
Mutation: A change in the sequence of a gene.
PCR test: A genetic test used to detect pre-mutations in a person's DNA.
Punnett square: A method of showing the potential offspring of two parents.
Sex chromosome: Chromosomes (X and Y) that determine an individual's gender.
Southern blot test: A genetic test that detects full mutations in a person's DNA.
Thymine: One of the four bases that make up DNA. Abbreviated with a 'T'.
Transmitting male: With reference to Fragile X, a transmitting male has a pre-mutation that he has passed to his daughter.
X-inactivation: A process in female mammals in which one of the two X chromosomes is "turned off."
fragile x syndrome and autism
Do You Know What Fragile X Is?
this is good video about fragile x
difference and ties between fragile x syndrome autism..
this is good video about fragile x
difference and ties between fragile x syndrome autism..
fragile x syndrome filetype pdf
fragile x syndrome filetype pdf: more information about fragile x sydrome there is a pdf online e-book on this site: please click here to download pdf document type of book now
fragile x syndrome
Created by Justin S., Julie and Brianna, students at the University of Missouri - Columbia for Genetic Diseases, Bio 2002, WS07
new gene linked to fragile x syndrome discovered
New Gene Linked To Fragile X Syndrome -- Suggests Potential Targets For Autism And Other Neurological Disorders
ScienceDaily (2008) — Scientists at The Scripps Research Institute have discovered a new gene involved in fragile X syndrome, a condition that often shares many symptoms of autism. The discovery may lead to new tests or treatments for several neurological disorders. click here to read full article at sciencedaily
ScienceDaily (2008) — Scientists at The Scripps Research Institute have discovered a new gene involved in fragile X syndrome, a condition that often shares many symptoms of autism. The discovery may lead to new tests or treatments for several neurological disorders. click here to read full article at sciencedaily
genetic disease and fragile x syndrome
Fragile x syndrome is caused alteration of the FMR1 gene located on chromosome X.
Males have one X chromosome and one Y, in women has two copies of chromosome X, the disease occurs only when both copies of the gene is altered , in women homozygous recessive. Women who have a healthy gene on one X and one altered on X are called heterozygous not develop symptoms and are healthy carriers, because they can still transmit the mutation to their children. The name of the disease stems from the fact that the X chromosome has a characteristic shrinkage.
Males have one X chromosome and one Y, in women has two copies of chromosome X, the disease occurs only when both copies of the gene is altered , in women homozygous recessive. Women who have a healthy gene on one X and one altered on X are called heterozygous not develop symptoms and are healthy carriers, because they can still transmit the mutation to their children. The name of the disease stems from the fact that the X chromosome has a characteristic shrinkage.
fragile x syndrome genetic disease
Fragile X syndrome genetic disease characterized by mental retardation in a more or less serious delays in the development of language and behavior disorders. With an incidence of 1 in 1200 males and 1 in 2000 females, is the most frequent cause of mental retardation after Down syndrome.
human genetic diseases caused by mutations
Fragile X syndrome (or syndrome Martin Bell) is a human genetic disease caused by mutation of the FMR1 gene on the X chromosome, this mutation in a male over in 4000 and a female at 6000. About 1 in 256 women are carriers of Fragile-X and can transmit it to their children. About 1 in 800 males are carriers of Fragile-X; their daughters will, in turn, carry the gene. It accounts with Down syndrome primacy as the most common genetic cause of mental retardation.
Normally, the FMR1 gene contains between 6 and 53 repeats of CGG codon (repetition of trinucleotidi). In individuals suffering from Fragile X syndrome, the FMR1 allele has more than 230 repetizioni of this codon. This level of expansion causes the methylation of cytosine in the promoter of the FMR1 gene, thus silencing the expression of the FMR1 gene. The methylation of the locus FMR1, which is located on chromosome band Xq27.3, causing at that point, the constriction and the fragility of the X chromosome, a phenomenon that gives its name to the syndrome.
Males with a FMR1 gene with a significant expansion of the CGG triplet with the symptoms of the disease, since you normally have only one copy of chromosome X. Females, by contrast, have two copies of chromosome X and therefore have a chance to own at least twice a functional allele. The women with an expanded FMR1 gene on one of the two X chromosomes may show some symptoms of the disease or be normal (Figure right on all'ereditarietà linked recessive X chromosome does not correspond exactly to the case of Fragile X syndrome , But it exemplifies the situation).
Apart from the mental retardation of varying degrees from moderate to severe, other obvious features of the syndrome are elongated face, large ears, large testicles (macrorchidismo), and low muscle tone. Behavioral characteristics may include stereotypical movements (for example, beat their hands) and atypical social development, particularly shyness and limited eye contact situations. Some individuals suffering from Fragile X syndrome are also in the diagnostic criteria of autism.
The mutation and methylation of the FMR1 gene leads to the abolition of production of the protein for which the FMR1 gene encoding, that FMRP (fragile-X mental retardation protein). FMRP is a protein binding to RNA (RNA-binding protein) expressed mainly in the testicles and brain tissues most affected by the syndrome. FMRP RNA is associated with major messengers coding neural protein, and regulates some essential aspects, such as transportation along the dendriti to the synapses and the translation into proteins. In the absence of FMRP, many of the target RNA messengers of the protein are more deregulated and are translated into protein. There are also new molecular functions of protein, such as adjusting the stability of messenger RNA.
Although there is still no cure for the syndrome, there is hope that a better understanding of its causes may lead to new therapies. Currently, the syndrome can be treated through behavioral therapy, special education, and when necessary, treatment of physical abnormalities. We advise people who have relatives suffering from Fragile X syndrome to contact the geneticists to assess the probability of having sick children, and to know the seriousness of the problems that may have affected the descendants of the syndrome.
Normally, the FMR1 gene contains between 6 and 53 repeats of CGG codon (repetition of trinucleotidi). In individuals suffering from Fragile X syndrome, the FMR1 allele has more than 230 repetizioni of this codon. This level of expansion causes the methylation of cytosine in the promoter of the FMR1 gene, thus silencing the expression of the FMR1 gene. The methylation of the locus FMR1, which is located on chromosome band Xq27.3, causing at that point, the constriction and the fragility of the X chromosome, a phenomenon that gives its name to the syndrome.
Males with a FMR1 gene with a significant expansion of the CGG triplet with the symptoms of the disease, since you normally have only one copy of chromosome X. Females, by contrast, have two copies of chromosome X and therefore have a chance to own at least twice a functional allele. The women with an expanded FMR1 gene on one of the two X chromosomes may show some symptoms of the disease or be normal (Figure right on all'ereditarietà linked recessive X chromosome does not correspond exactly to the case of Fragile X syndrome , But it exemplifies the situation).
Apart from the mental retardation of varying degrees from moderate to severe, other obvious features of the syndrome are elongated face, large ears, large testicles (macrorchidismo), and low muscle tone. Behavioral characteristics may include stereotypical movements (for example, beat their hands) and atypical social development, particularly shyness and limited eye contact situations. Some individuals suffering from Fragile X syndrome are also in the diagnostic criteria of autism.
The mutation and methylation of the FMR1 gene leads to the abolition of production of the protein for which the FMR1 gene encoding, that FMRP (fragile-X mental retardation protein). FMRP is a protein binding to RNA (RNA-binding protein) expressed mainly in the testicles and brain tissues most affected by the syndrome. FMRP RNA is associated with major messengers coding neural protein, and regulates some essential aspects, such as transportation along the dendriti to the synapses and the translation into proteins. In the absence of FMRP, many of the target RNA messengers of the protein are more deregulated and are translated into protein. There are also new molecular functions of protein, such as adjusting the stability of messenger RNA.
Although there is still no cure for the syndrome, there is hope that a better understanding of its causes may lead to new therapies. Currently, the syndrome can be treated through behavioral therapy, special education, and when necessary, treatment of physical abnormalities. We advise people who have relatives suffering from Fragile X syndrome to contact the geneticists to assess the probability of having sick children, and to know the seriousness of the problems that may have affected the descendants of the syndrome.
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