Spinal Cerebral Ataxia Type - 7

What is Spinal Cerebellar Ataxia Type 7 (SCA7) test?

Spinal Cerebellar Ataxia Type 7 (SCA7) is a rare genetic disorder that causes progressive problems with movement coordination and vision loss. It is one of the autosomal dominant spinocerebellar ataxias, caused by an abnormal CAG trinucleotide repeat expansion in the ATXN7 gene.

This test is a genetic analysis that checks for the number of CAG repeats in the ATXN7 gene, using a blood sample collected in an EDTA (purple-top) tube, which preserves the DNA for testing.

Why consider Spinal Cerebellar Ataxia Type 7 (SCA7) test?

This test is considered when:

• A person presents with progressive coordination problems and vision loss.
• There is a family history of SCA7 or similar neurodegenerative and visual symptoms.
• To confirm a diagnosis of SCA7 in a symptomatic individual.
• For predictive or carrier testing in at-risk family members.
• As part of a differential diagnosis when ruling out other types of spinocerebellar ataxia.

Who should get tested for Spinal Cerebellar Ataxia Type 7 (SCA7) test?

This test may be recommended for:

• Individuals with progressive gait ataxia, slurred speech, and visual impairment.
• People with a family history of SCA7 or early-onset blindness and ataxia.
• Parents or siblings of someone diagnosed with SCA7, especially for reproductive planning.
• Individuals referred by a neurologist or genetic counselor for suspected hereditary ataxia.

More Information

OTHER NAMES: SCA7 Genetic Test, ATXN7 Gene Repeat Expansion Test, Spinocerebellar Ataxia Type 7 DNA Analysis, Hereditary Ataxia Type 7 Test

Spinocerebellar Ataxia Type 7 (SCA7) is a genetic disorder characterized by progressive ataxia (loss of coordination and balance), progressive vision loss due to degeneration of the retina, gradual worsening of motor control, speech, and eye movements.

It is part of a broader group called spinocerebellar ataxias (SCAs), and SCA7 is distinct for its involvement of the retina, which can lead to blindness.