Fragile X Syndrome
Fragile X Syndrome (FXS) is a genetic condition that significantly impacts intellectual and developmental functioning. It stands as the most common inherited cause of intellectual disability and autism spectrum disorder. Affecting approximately 1 in 4,000 males and 1 in 8,000 females, FXS is rooted in a genetic mutation on the FMR1 gene. This gene is crucial for producing a protein essential for normal brain development. Disruption in the production of this protein leads to the symptoms associated with Fragile X Syndrome.
This article provides a comprehensive overview of Fragile X Syndrome, including detailed explanations, clinical utility, recommendations for testing, and the offerings from MapmyGenome.
Fragile X Syndrome is caused by a repeat expansion in the FMR1 gene located on the X chromosome. This gene is responsible for producing the fragile X mental retardation protein (FMRP), which plays a critical role in synaptic plasticity, a key process for learning and memory.
In individuals with Fragile X Syndrome, the FMR1 gene has an expanded CGG repeat sequence, which leads to methylation and silencing of the gene. As a result, the production of FMRP is disrupted or absent. This lack of FMRP affects brain function, leading to the characteristic features of Fragile X Syndrome.
Symptoms can vary but often include:
- Intellectual disability or developmental delay
- Autism spectrum disorders
- Hyperactivity and impulsivity
- Social and emotional difficulties
- Specific physical features, such as a long face, large ears, and a prominent jaw
Fragile X Syndrome can also have implications for fertility and reproductive planning, as the condition can be passed down from parents to children.
Clinical Utility
For Individuals & Couples:
- Unexplained Infertility: Testing for Fragile X Syndrome is beneficial for individuals and couples experiencing unexplained infertility. FXS can be a contributing factor to fertility issues, and identifying the genetic cause can provide insights into treatment options.
- Family History: If there is a known family history of Fragile X Syndrome, genetic testing can help assess carrier status and potential risks for offspring. This information is crucial for family planning and managing the risk of passing the condition to future generations.
For Couples Undergoing IVF:
- Carrier Status: During IVF procedures, testing for Fragile X Syndrome can identify carrier status, which is essential for making informed decisions about embryo selection and assisted reproductive techniques. Carrier screening helps guide the use of genetic technologies to prevent the transmission of the syndrome.
For Couples Experiencing Recurrent Pregnancy Loss (RPL):
- Genetic Factors: In cases of recurrent pregnancy loss, understanding whether Fragile X Syndrome is a factor can aid in diagnosing the underlying cause of pregnancy loss. Genetic counseling and appropriate interventions can then be implemented to manage future pregnancies.
When to Consider Testing
Infertility:
- Unexplained Infertility: If traditional tests have not identified the cause of infertility, testing for Fragile X Syndrome may reveal underlying genetic issues contributing to the problem.
- Elevated FSH Levels: For women with fertility problems related to elevated Follicle Stimulating Hormone (FSH) concentrations, testing for Fragile X Syndrome can provide insights into potential genetic causes.
Reproductive Planning:
- Carrier Risk: For individuals who want to understand their risk of having offspring affected by Fragile X Syndrome, testing is crucial. This is particularly important for those with a family history of the syndrome or known genetic carriers.
Young Women with Reproductive Issues:
- Low Ovarian Reserve or Early Menopause: Women experiencing low ovarian reserve or early menopause should consider testing for Fragile X Syndrome as part of their fertility evaluation.
MapmyGenome Offerings
At MapmyGenome, we provide comprehensive testing services for Fragile X Syndrome to support individuals and families in making informed decisions. Our offerings include:
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Genetic Testing for Fragile X Syndrome: Utilizing advanced technologies, we perform detailed genetic analysis to detect mutations in the FMR1 gene. This includes assessing the number of CGG repeats and determining carrier status.
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Counseling and Support: Our expert genetic counselors provide guidance through the testing process, helping you understand the results and implications for family planning and reproductive health.
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Comprehensive Reports: We offer detailed reports that include information on mutation status, carrier status, and recommendations for management and further testing.
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Reproductive Planning Assistance: For couples undergoing IVF or experiencing recurrent pregnancy loss, we provide insights into genetic risks and support for making decisions about reproductive options.
Test specifications
Technique |
Variant types |
TAT |
Sample Requirements |
TP - PCR |
STR |
3 weeks |
EDTA Blood, Amniotic Fluid, CVS (In case of Prenatal) and 3-4 ml Maternal Blood in EDTA for MCC |