Curation ALS1 NIPA1

Gene NIPA
Disease ALS1
Inheritance AD
Score

2 + 1 = 3 / 18

Genetic + experimental = total
Classification
0
18
Refuted
Moderate
Definitive
Last Updated 06/06/2025
Pubs Reviewed 3
Publication Span 2.33 years
Publication Interval 2.33 years
Curator(s) Macayla Weiner, Laurel Hiatt, Harriet Dashnow
Description

The NIPA1 exon 1 GCG/polyalanine repeat has been reported as an ALS risk or modifier locus, with some European cohorts showing enrichment or survival effects for long alleles (≥9 or >8 GCG repeats), whereas African-ancestry and broader Project MinE STR studies did not confirm an ALS susceptibility or age-at-onset association. The evidence is conflicting and largely association-based, with limited direct locus-specific evidence, supporting the disputed classification. The evidence does not currently support a Mendelian association between the NIPA1 repeat and ALS.

Genetic evidence

Total: 2

Category
Type
Citation
Score
Details
Singular Evidence
Probands
0

6 patients with the NIPA1 expansion, co-occuring with a C9orf72 expansion. The source reports cohort-level NIPA1 repeat genotyping but does not describe individual NIPA1-expanded ALS probands with phenotype, family, or functional details suitable for singular proband scoring. Therefore, a score of 0 is assigned for this evidence.

Collective Evidence
Computational
0

ExpansionHunter WGS analysis of Southern African ALS cases and African controls found similar NIPA1 GCG-repeat distributions (p = 0.67); long alleles (≥9 GCG repeats) were rare in Africans and not associated with ALS, while 9–10-repeat alleles were more common in European than African controls (6% vs 0.4%, p = 0.016). Score of 0 assigned as this evidence does not support an association between the NIPA1 repeat and ALS.

Statistics
Case-control data
2

Project MinE STR analysis found NIPA1 ≥9-repeat alleles in 232 ALS cases (4.6%) and 78 controls (4.6%), with no significant ALS susceptibility association; NIPA1 showed only a nominal survival association. They used two methods of variant detection.

Experimental evidence

Total: 1

Category
Type
Citation
Score
Details
Function
Protein interaction
1

Authors found altered protein to protein interactions and sequesteration of RNA-binding protein.

Maximum score caps apply at evidence type, category, and supercategory levels, so section totals may be lower than the raw sum of row scores.