Neurogenetics Reference Lab · Teaching Example
- Panel
- Episodic Ataxia / Channelopathy Panel (32 genes)
- Report ID
- TEACH-0008
- Indication
- Episodic ataxia and migraine starting in adolescence.
- Specimen
- Peripheral blood, EDTA · Received 2026-03-18
- Reported
- 2026-04-02
- Methodology
- Targeted capture NGS, mean depth 230×. Trio not performed.
Patient (anonymized teaching example)
Age 17 years · Male · Mixed ancestry
Clinical: Episodic ataxia attacks lasting hours since age 13. Coincident migraine with aura. Normal neurological exam between attacks. Family history: mother reports occasional vertigo, untested.
Reportable Variants
| Gene | Variant | Zygosity | Condition (Mode) | Origin | Classification |
|---|---|---|---|---|---|
Interpretation
A heterozygous CACNA1A variant c.4762G>A (p.Gly1588Arg) was identified. The variant is absent from gnomAD population databases (PM2_Supporting) and predicted deleterious by computational tools (PP3). However, this variant has not been previously reported in patients, has not been functionally characterized, and . The clinical phenotype is consistent with CACNA1A-related episodic ataxia, but the evidence is insufficient to classify the variant as Likely Pathogenic. Classification: (VUS). This variant .
Recommendations
- •Parental testing (both parents) — the single most informative next step. If the variant is de novo, PS2 applies and the classification likely upgrades to Likely Pathogenic. If inherited from an affected parent, segregation with phenotype adds evidence; if inherited from an unaffected parent, evidence shifts toward Benign.
- •Clinical follow-up — do NOT alter management based on this VUS alone.
- •Reassessment in 1–2 years — new case reports or functional studies may reclassify.
- •If the variant is later upgraded to P/LP, acetazolamide is the first-line treatment for episodic ataxia type 2.