Table 1.

Molecular Genetic Testing Used in ARSACS

Gene 1MethodProportion of Pathogenic
Variants 2 Detectable by Method
SACS Sequence analysis 3, 4~95% 5
Gene-targeted deletion/duplication analysis 6~5% 7
1.
2.

See Molecular Genetics for information on allelic variants detected in this gene.

3.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

4.

Note: Targeted analysis for pathogenic variants in SACS including c.8844delT and c.7504C>T (p.Arg2502Ter) can be performed first in individuals of northeastern Quebec ancestry [Mercier et al 2001].

5.

Data derived from LOVD3 Database and from Human Gene Mutation Database [Stenson et al 2020]

6.

Gene-targeted deletion/duplication analysis detects intragenic deletions or duplications. Methods used may include a range of techniques such as quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and a gene-targeted microarray designed to detect single-exon deletions or duplications. Gene-targeted deletion/duplication testing will detect deletions ranging from a single exon to the whole gene; however, breakpoints of large deletions and/or deletion of adjacent genes (e.g., those described by Dougherty et al [2018]) may not be detected by these methods.

7.

From: ARSACS

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