Is CTSA p.Arg25Gln (c.74G>A) pathogenic?

CTSA p.Arg25Gln (c.74G>A) is classified Uncertain significance in CTSA (ClinVar, Single submitter, 1 submitter; last evaluated 2021-08-30). AlphaMissense: likely benign (0.0896); Very rare (popmax 0.00839%, nfe); Associated with galactosialidosis.

What condition is associated with CTSA p.Arg25Gln (c.74G>A)?

CTSA p.Arg25Gln (c.74G>A) is associated with galactosialidosis (ClinVar).

How common is CTSA p.Arg25Gln (c.74G>A) in the general population?

CTSA p.Arg25Gln (c.74G>A) is very rare (popmax 0.00839%, nfe) (gnomAD).

How is Galactosialidosis inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about CTSA p.Arg25Gln (c.74G>A)?

AlphaMissense predicts likely benign (score 0.0896) — an in-silico prediction, not a clinical call.

CTSA p.Arg25Gln

c.74G>A · rs746200419 · VCV1388738

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0896 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00839%, nfe)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

galactosialidosis

Computational evidence

Protein change
AlphaMissense	0.0896	likely benign
REVEL	0.026	moderately benign-leaning
SaProt	LLR -7.88	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.49	GERP -2.8
Regional constraint	o/e 0.92	unconstrained · MANE · 1,710 bp · p 0.19 · regional, not allelic
Overall
CADD	11.28	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00839% European (non-Finnish) · 99/1,179,834 alleles

Filtering AF 0.00702% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00652%

Overall 0.0062% 100/1,612,058 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00839%	11,918
African / African-American	0.00133%	74,930

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: CTSA
Protein: p.Arg25Gln
Coding: c.74G>A
MANE Select: NM_000308
dbSNP: rs746200419
Type: single nucleotide variant
Location: chr20:45891642 (GRCh38)
Gene constraint: LOEUF 0.851 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 94.59 · 12 PDB

Full CTSA gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

galactosialidosis — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Galactosialidosis (Orphanet):

Inheritance: Autosomal recessive
Onset: All ages

Similar variants

CTSA p.Arg25Ter Likely pathogenic ★ same residue
CTSA c.1-2A>G Pathogenic/Likely pathogenic ★★ same condition
CTSA c.358-2A>G Likely pathogenic ★★ same condition
CTSA c.601-2A>G Pathogenic/Likely pathogenic ★★ same condition
CTSA c.692+3A>G Pathogenic ★★ same condition
CTSA c.948+1G>A Likely pathogenic ★★ same condition
CTSA p.Arg375Ter Pathogenic/Likely pathogenic ★★ same condition
CTSA p.Cys256Ter Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/ctsa-p-arg25gln (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown