How is fragile X syndrome inherited? Inheritance of fragile X syndrome is complicated. Individuals with a family history of this disorder should consult a genetic counselor to learn more about the risks of passing the disorder to their children.

• Normal number of repeats:

 Individuals with a normal number of repeats (5 to 40) cannot pass fragile X syndrome to their offspring. The number of repeats generally does not change when passed from parent to child.

• Intermediate number of repeats:

 When a person has 41 to 58 repeats (called the gray zone), the number of repeats can sometimes increase slightly when passed from parent to child. These parents are not at risk of having a child with fragile X syndrome. However, the number of repeats can grow with each generation, so their grandchildren could be at risk.

• Premutation:

 Individuals with 59 to 200 repeats have a premutation (3). Both men and women can be carriers of a premutation. About 1 in 250 women and 1 in 800 men carries a premutation (8). However, only women who carry a premutation are at risk for having a child with fragile X syndrome.

A mother with a premutation has a 50-percent chance of passing the abnormal gene to her baby in each pregnancy. Some children who inherit the abnormal gene have a premutation and no symptoms of fragile X syndrome. However, the number of repeats is likely to expand when the gene is passed from mother to child. So the number of repeats can increase from a premutation to a full mutation (more than 200 repeats). Children with a full mutation have fragile X syndrome.

A father with a premutation passes it to all of his daughters but to none of his sons. Daughters generally have no symptoms of fragile X syndrome, but they are carriers of a premutation that they can pass on to their own children. Fathers with a premutation do not pass it to their sons because males do not get an X chromosome from their father.

• Full mutation:

 Individuals with more than 200 repeats have a full mutation. A woman with a full mutation has a 50-percent chance of passing it to her baby in each pregnancy. Men with a full mutation generally do not reproduce.

Happy Thursday to all!!!!!
hows life going?? I am posting after a gap..but today I am with a great information for all, who are searching information regarding Fragile X diagnosis for their kids, would be mothers or any relatives...We are referring the centers who are using  Amplidex PCR Based Fragile X Diagnosis Kit developed by a team of ASURAGEN. It is having many advantages over other home brew test and Southern Blots test for Fragile X. 
In Indian 4 centers are using this--

1] Dr. Madhulika Kabra http://www.aiims.ac.in/aiims/departments/pediatrics/genetics.htm

2] Dr. Parag Tamhankar, http://www.nirrh.res.in/centres/GRC/projects.htm

3] Dr. Jayanthi Undmatla, http://sandor.co.in/pro-diagnostics.html 

4) Dr Renu Saxena,  http://www.sgrh.com/search/details.aspx?id=55 

A good new for those, who cannot afford the cost, NIRRH (ICMR) centre, Mumbai, now they are offering the test free of cost for the sampleswhich are positive based on clinical, pedigree analysis, based on cytogenetic tests etc. They will provide you the finer details of the patients which only Amplidex PCR assay can provide.

So, it will be very beneficial to your patients.http://www.appliedbioscience.com/docs/ASGN/FragileX_case_record_form.doc

Here you can download the "Fragile X case record form" which is to be sent along with the samples.

If you want any information or any kind of help, please don't hesitate, call me on 022-29660575, or mail me on sales@appliedbioscience.com..

To day I am going to write a case about which I got to know from one government research center in India. They got one case of Fragile X kid, whose mother was a carrier but the couple was not aware of that. When they observe something abnormal in their first kid, they planned for their second kid (at that time the first kid was 2 years and 4 months old). Mother found herself unable to conceive and after testing they got to know about Fragile X. But it was too late, they tried for egg donor and after 2 trails, they had a miracle of 1 normal kid.
We can learn from this example, and spread the awareness to wards Fragile X syndrome and its testing. Sometimes cost should not be the concern when it is about your babies...isn't it, but still here in India, a lot to be done in this regard. Couples, if they go for genetic testing (rare), they just want the screening...whether they are positive or negative and not the details. they don' know that the details may affect the risk of expansion in next generation........so friends....spread this...share this with your friends, families, colleagues and take active participation in revolution of Fragile X Diagnosis...

Have a Nice Week!!!!!!!!!!!!!!!!
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Hii, all !!!!!!!!,  very sad, nobody yet posted any comment on my very first post...while reading about Fragile X, one question stroke in my mind---mothers with no knowledge of fragile X will may have many questions in their mind before and after their genetic test...so, today I am posting some Questions which may come to your mind and their answers...

Q.1 What is my risk of being a fragile X carrier?
About 1 in 200 women is a fragile X carrier. Your chances of being a fragile X carrier may be much higher depending on your family history. If you have a family history of fragile X syndrome or of intellectual disability from an unknown cause, you are more likely to be a fragile X carrier.

Men can also be fragile X carriers, but it's usually only when the woman is the carrier that the children get full fragile X syndrome.


Q.2 Should you or your future child be tested for fragile X?
If you are pregnant and a fragile X carrier, you may want to have a prenatal test for fragile X syndrome. Fragile X testing also should be considered for anyone who has a chromosome test that shows fragile X. The chromosome test is no longer performed routinely, but if someone in your family was positive for this test in the past, that family member should consider DNA testing to confirm the results.


Q.3 Should a child with intellectual disability be tested for fragile X?
Fragile X testing should be considered for any child who has been diagnosed with intellectual disability, developmental delay or autism. This is especially true if there is a family history of fragile X or some other form of intellectual disability from an unknown cause, or if the child has any physical features that would suggest fragile X syndrome.


Q.4 If I have the fragile X gene, can I have children who don't have it?
If you are a woman carrying a fragile X pre-mutation, you have a 50% chance of passing on the affected gene to each child you have. If you are a man with a pre-mutation, you will pass it on to your daughters, but not your sons. In the unlikely event that both parents carry a pre-mutation, the chances of getting a changed gene are 100% for their daughters and 50% for their sons.


Q.5 While I'm pregnant, can I determine the risk my baby has of developing fragile X?
To discover whether your unborn child has inherited changes in the fragile X gene, you and your partner can get prenatal testing. Prenatal DNA testing is available if you have a family history of fragile X or of unexplained intellectual disability. There are two common ways of obtaining DNA from fetal cells:

   1. Chorionic villus sampling is performed early in the pregnancy — between 10 and 13 weeks. A physician takes a sample of chorionic villus cells from part of the placenta that contains fetal cells.
   2. Amniocentesis is performed after 15 weeks. The physician obtains fetal cells from the amniotic fluid that surrounds the fetus.

You can also get tested before a pregnancy using preimplantation genetic diagnosis (PGD). PGD is done by in vitro fertilization (IVF). Each fertilized embryo is tested to see if it has the fragile X mutation. Only the embryos without a mutation are implanted into the mother.

Talk with your obstetrician or a genetic counselor about your options.


Q.6 If I am a fragile X carrier, could I give birth to a girl with the disease?
There is a 100% chance a male pre-mutation carrier would pass on the gene, but his daughter would only be a carrier and not have the disease. There is a 50% chance that a female pre-mutation carrier will pass the expanded gene on to her daughter. If the number of repeats stays the same, the daughter also will be a pre-mutation carrier. If the number of repeats increases to the more than 200, then the daughter might be affected. Also, a girl with a full mutation might have symptoms of fragile X, including intellectual disability, but symptoms are less severe in girls because they have an extra X chromosome to fall back on.


Q.7 If I DON'T have the fragile X gene, can I have children who DO have the gene?
If you're not a carrier, then your children cannot inherit the gene from you. But there is always the possibility that the number of repeats in the gene could increase from one generation to the next. We all have some repeats in the FMR1 gene. It would be very unusual, however, for the gene to expand from a normal number of repeats to a full mutation in one generation.


Q.8 Is there any harm in finding out if I am a carrier?
Possibly. You may feel upset if you learn that you carry a gene that could potentially cause intellectual disability in your future children. However, it is important to note that carriers generally have normal intellectual abilities and normal appearance.

Well, i tried to cover up all probable questions, but if you have any , feel free to ask me here, and I'll also try to post some more,,,,,,,byeeee have a nice weekend.....:-)

Hii friends!!!!!!!, I am new here and very much surprised and happy to read all the blogs. Here, many have shared their happy & sad stories of their own experiences. I too have one to share with all of you.
I am Indian, the country of many religions, languages, festivals and many more. It has many unique things which other countries do not have, but have Fragile X syndrome as all other countries. 


The Fragile X syndrome is caused by a "fragile" site at the end of the long arm of the X-chromosome. It is a genetic disorder that manifests itself through a complex range of behavioural and cognitive phenotypes and is directly related to developmental disorders or delays, the signs for the disease are recognized when the child shows reluctance or inability to meet the developmental milestones as he grows up.It is the result of genetic mutation which varies considerably in severity among patients. 
Fragile X syndrome is the most common cause of inherited mental retardation. Although it is a X-linked recessive trait with variable expression and incomplete penetrance, 30% of all carrier women are affected.   
      
The diagnosis of Fragile-X syndrome is made through the detection of errors in the FMR1 gene. Over 99% of individuals have a full mutant FMR1 gene. Tests used for diagnosis include chromosome analysis and various protein tests. Diagnosis is usually made when young, and there is no current cure for this illness. Early diagnosis of the syndrome call allow for therapeutic interventions like speech therapy, occupational therapy, psychotherapy and special education, that can considerably improve the quality of the patients' life.


As, in current scenario, we don't have any cure, I should suggest would be mothers to go for genetic testings. If you are pregnant and a fragile X carrier, you may  have a child with the same syndrome after his/her birth. If you are a woman carrying a fragile X pre-mutation, you have a 50% chance of passing on the affected gene to each child you have. If you are a man with a pre-mutation, you will pass it on to your daughters, but not your sons. In the unlikely event that both parents carry a pre-mutation, the chances of getting a changed gene are 100% for their daughters and 50% for their sons. To discover whether your unborn child has inherited changes in the fragile X gene, you and your partner can get prenatal testing. Prenatal DNA testing is available if you have a family history of fragile X or of unexplained intellectual disability. There are two common ways of obtaining DNA from fetal cells....I think is is suffieicent for the day...will come back with more helpfull facts and information for this blog readers....