(Spino Cerebellar Ataxia) SCA 8

1. What is the Spino Cerebellar Ataxia (SCA 8) Test?
The Spino Cerebellar Ataxia (SCA 8) test is a genetic screening used to detect mutations in the ATXN8 gene, which is responsible for causing SCA 8. Spino Cerebellar Ataxia is a rare, inherited neurological disorder that causes progressive loss of muscle coordination and other motor functions due to damage to the cerebellum. The SCA 8 test is important for confirming the presence of genetic mutations in individuals with suspected symptoms of cerebellar ataxia in Dubai.

2. Purpose / Clinical Significance:
The SCA 8 test has multiple purposes and clinical significance:

• Early Diagnosis: It is used for the early diagnosis of Spino Cerebellar Ataxia 8 (SCA 8), a rare but progressive disorder.

• Genetic Carrier Screening: It helps identify individuals who carry the mutation of SCA 8, even if they are asymptomatic.

• Family Planning: It is essential for genetic counseling and family planning, allowing couples to understand the risk of passing SCA 8 to their children.

• Differentiation of Neurological Disorders: It assists in differentiating SCA 8 from other types of Cerebellar Ataxia or motor disorders, enabling precise diagnosis and treatment.

3. Principle of the Test:
The SCA 8 test works by analyzing the DNA for mutations in the ATXN8 gene. The ATXN8 gene contains a CTG repeat expansion, which can vary in length. An abnormally long repeat is responsible for causing SCA 8. The test detects these genetic mutations and identifies the presence of SCA 8 in an individual. The test uses polymerase chain reaction (PCR) to analyze DNA and sequencing techniques to detect mutations in the gene.

4. Specimen Requirements:
The SCA 8 genetic test requires a biological specimen for analysis:

• Blood Sample: A small blood sample is the most common method for genetic testing. The sample is processed in a laboratory for DNA extraction.

• Saliva Sample: In some cases, a saliva sample may be used for DNA extraction, offering a non-invasive option.

• Genetic Material: The sample is processed to isolate DNA for the genetic test to identify the ATXN8 gene mutation.

5. Common Methods for Testing:
The SCA 8 test utilizes several methods to detect genetic mutations:

• Polymerase Chain Reaction (PCR): PCR is used to amplify the region of DNA where the CTG repeat is located, helping detect the SCA 8 mutation.

• Sequencing Techniques: DNA sequencing methods like Sanger sequencing or Next-Generation Sequencing (NGS) are used to confirm the presence of abnormal CTG repeats in the ATXN8 gene.

• Repeat-Primed PCR: This method is specifically designed to measure the CTG repeat expansion, which is characteristic of SCA 8.

6. Whom and Why Should Take the SCA 8 Test?
The SCA 8 genetic test is recommended for:

• Individuals with symptoms of ataxia: People experiencing motor coordination issues, balance problems, or unexplained muscle weakness may benefit from genetic testing for SCA 8.

• Family members with a history of neurological disorders: If someone has a family history of Spino Cerebellar Ataxia or other types of cerebellar ataxia, they may be at higher risk of carrying the SCA 8 mutation.

• Genetic counseling: Those considering starting a family or undergoing family planning may take the test to assess the risk of passing the genetic disorder to their children.

• Asymptomatic carriers: Individuals who are carriers of the SCA 8 gene mutation but show no symptoms may also be tested for SCA 8 to understand their genetic risk.

Why take the test?

• Diagnose SCA 8 early: The SCA 8 test provides an early diagnosis for individuals who may be unaware of their condition.

• Genetic counseling and family planning: It helps individuals make informed decisions about having children by understanding the genetic risk.

• Differentiating neurological disorders: Helps doctors identify SCA 8 and differentiate it from other neurological conditions with similar symptoms, ensuring the correct treatment plan.

7. Interpretation of Results:

• Normal result: A normal result means no mutations were found in the ATXN8 gene. This indicates that the person does not have SCA 8 or carry the gene mutation for it.

• Positive result: A positive result indicates the presence of an expanded CTG repeat in the ATXN8 gene, confirming the diagnosis of SCA 8. If only one allele is affected, the individual may be an asymptomatic carrier, while two affected alleles may indicate the presence of symptomatic SCA 8.

• Carrier status: If the test indicates that a person is a carrier of the SCA 8 gene mutation, they may not experience symptoms but have the potential to pass the condition to their children.

8. Reference Range:

• Normal (no mutation): No abnormal CTG repeat expansion is detected, and the individual is considered not affected by SCA 8.

• Carrier status: A carrier has one abnormal allele with a CTG repeat expansion but may remain asymptomatic.

• Affected individual: An individual with two expanded CTG repeats may develop SCA 8 and experience symptoms over time.

9. Follow-up Testing:
If the SCA 8 test result is positive or indicates a genetic risk, follow-up testing may include:

• Neurological evaluation: To assess the presence of motor coordination problems, balance issues, or other symptoms of SCA 8.

• Brain MRI: Used to assess the cerebellum for signs of degeneration, which may be indicative of SCA 8.

• Genetic counseling: For individuals with positive test results, genetic counseling is recommended to understand the implications for family planning and manage expectations.

• Further genetic testing: In some cases, additional tests for other types of Cerebellar Ataxia or mutations may be needed.

10. Conclusion:
The Spino Cerebellar Ataxia (SCA 8) genetic test is an essential tool for diagnosing this rare neurological disorder, identifying genetic carriers, and providing valuable information for family planning. If you or a family member are showing symptoms of cerebellar ataxia or have a family history of neurological disorders, this genetic test in Dubai can offer crucial insights. Early diagnosis and genetic counseling can lead to better management of the disease and help prevent complications. For those seeking genetic testing in Dubai, the SCA 8 test provides a clear and accurate pathway to understanding your genetic health and planning for the future.