SCA (Spino Cerebellar Ataxia) Comprehensive Profile (1.2.3.6.7.12)

The SCA Comprehensive Profile (Types 1, 2, 3, 6, 7, 12) is a targeted genetic panel that detects pathogenic trinucleotide repeat expansions in six of the most common and clinically significant forms of autosomal dominant spinocerebellar ataxia (SCA) — progressive neurodegenerative disorders affecting coordination, balance, speech, and movement.

This test analyzes key genes:

• SCA1 (ATXN1)
• SCA2 (ATXN2)
• SCA3/MJD (ATXN3) – Most common worldwide
• SCA6 (CACNA1A)
• SCA7 (ATXN7) – Associated with vision loss
• SCA12 (PPP2R2B)

Using advanced PCR and fragment analysis, this assay measures the number of CAG repeats in each gene to determine whether an expansion exists providing a definitive diagnosis for patients with unexplained gait instability, tremors, or family history of ataxia.

Offered at Lab Tests Dubai, this comprehensive profile supports early detection, accurate classification, and informed family planning for individuals and families impacted by inherited neurological conditions.

Why You Need This Test

You need the SCA Comprehensive Profile if:

• You or a family member has progressive difficulty walking, tremors, or poor coordination
• You’ve been diagnosed with idiopathic cerebellar ataxia with no known cause
• There’s a family history of ataxia or unexplained neurological decline
• You’re experiencing slurred speech (dysarthria), dizziness, or abnormal eye movements
• A relative has tested positive for one of these SCA types
• You’re considering predictive testing due to family risk
• You’re being evaluated by a neurologist for movement disorders

This test helps confirm or rule out the most prevalent genetic causes of adult-onset ataxia guiding treatment, surveillance, and reproductive decisions.

Symptoms That Indicate This Test

Consider booking this test if you experience:

• Gradual loss of coordination (ataxia) while walking or using hands
• Slurred or slow speech
• Unsteady gait, frequent falls, or imbalance
• Abnormal eye movements (nystagmus)
• Muscle stiffness, spasticity, or tremors
• Vision problems (especially in SCA7)
• Family members with similar symptoms or confirmed SCA mutations

Symptoms often begin subtly in adulthood (30s–50s) and worsen over time making early diagnosis critical for managing independence and quality of life.

Gene Repeats & Neurological Function

Your body naturally produces proteins essential for cerebellar function the brain region responsible for motor control. The SCA-related genes contain repetitive DNA sequences (CAG repeats) that are normally stable.

However, when these repeats expand beyond normal limits:

• Intermediate (premutation): May be unstable during inheritance
• Pathogenic (expanded): ≥45–87+ repeats (depending on gene)

… they produce abnormal proteins with long polyglutamine tracts that accumulate in neurons particularly in the cerebellum and brainstem leading to toxic gain-of-function effects and progressive cell death.

This test measures the exact number of CAG repeats in all six genes identifying disease-causing expansions even before symptoms appear.

What Happens If Untreated / Undiagnosed

Without diagnosis:

• Symptoms may be misdiagnosed as MS, Parkinson’s, or aging
• Families remain unaware of their hereditary risk
• No access to support groups, physical therapy, or clinical trials
• Risk of passing the mutation to 50% of offspring (autosomal dominant inheritance)
• Delayed intervention reduces long-term mobility and independence

While there is no cure yet, early identification allows for:

• Physical, occupational, and speech therapy
• Fall prevention strategies
• Genetic counseling
• Participation in emerging therapies and research

How to Prepare for the Test

Preparation is simple:

• No fasting required

• Continue regular medications

• Avoid blood transfusions within 72 hours (can affect DNA results)

• Sample Requirements:

• 4 mL whole blood (minimum 3 mL) collected in 2 Lavender-top (EDTA) tubes

• Must be labeled with full name, DOB, and collection date

• Mandatory Documentation:

• Completed Genomic Test Request Form (TRF)

• Signed Informed Consent Form

• Detailed clinical history, including:

  • Age of symptom onset
  • Family history of ataxia or neurological disease
  • Neurological exam findings or MRI reports

We offer home blood collection across Dubai & UAE performed by trained medical staff.

Test Overview