Genomic Unity® Case Study
Overview
Patient:
Female in her mid 60’s
Clinical presentation:
Hydrocephalus, spastic gait, ataxia, dystonia, stiff shoulders, obstructive sleep apnea, obesity, low back pain, thrombocytopenia, polycythemia, anemia, hyperlipidemia
Testing strategy:
Variantyx whole genome testing with combined short and long-read sequencing
Key finding:
BEAN1 repeat expansion
Clinical outcome:
Diagnosis established
Why Genomic Unity® was the right choice
A patient presenting with long-standing severe congenital hydrocephalus, spastic gait, dystonia, and ataxia sought consultation. Given the significant symptom overlap among hereditary ataxias and the disorder’s heterogeneous nature, testing with broad coverage of repeat expansion genes was recommended.
Genomic Unity® was selected because it delivers the most comprehensive genomic insight, including analysis of 20 ataxia-associated repeat expansion genes, from the start while:
- Reducing time to diagnosis
- Avoiding unnecessary testing
- Supporting the highest standard of patient care
Diagnostic finding: Spinocerebellar ataxia 31
Variantyx Genomic Unity® identified a pathogenic, fully expanded BEAN1 allele with 152-203 TGGAA repeats.
An uncertain, intermediate expanded FGF14 allele with 190-205 GAA repeats was also identified.
Uniform data from long-read WGS clearly identified both the BEAN1 (top) and FGF14 (bottom) expansions.
Impact on clinical care
Established a definitive diagnosis, providing insight into possible progression.
Variant spotlight: Repeat expansions
Detection challenges:
Repeat expansions, the most common cause of hereditary ataxias, can not be detected by standard genetic tests, including panels and exomes. And even most genomes.
While repeat expansions can be detected by PCR and Southern blotting, BEAN1 would have to be specifically targeted. Very few available ataxia tests are able to overcome the challenges of this locus.
Why Genomic Unity®
- Detects all major variant types in a single test including small sequence changes, structural variants, mitochondrial variants, and repeat expansions – which is critical for first-line testing of ataxia patients.
- Offers targeted and comprehensive testing options that combine short and long-read analysis expanding detection capabilities with 20 ataxia repeat expansion genes, including BEAN1 and FGF14. Variantyx is one of the first labs to offer BEAN1 testing.
Additional similar cases
Genomic Unity® – Biallelic RFC1 expansion confirms clinical CANVAS diagnosis
Genomic Unity® – Biallelic FGF14 expansions explain progressive gait imbalance
Genomic Unity® – Friedreich ataxia diagnosis enables access to treatment options
