Is CTSW p.Val203Ala (c.608T>C) pathogenic?

CTSW p.Val203Ala (c.608T>C) is classified Uncertain significance in CTSW (ClinVar, Single submitter, 1 submitter; last evaluated 2025-11-26). AlphaMissense: likely benign (0.2692); Ultra-rare (popmax 0.0274%, sas).

How common is CTSW p.Val203Ala (c.608T>C) in the general population?

CTSW p.Val203Ala (c.608T>C) is ultra-rare (popmax 0.0274%, sas) (gnomAD).

What do computational predictors say about CTSW p.Val203Ala (c.608T>C)?

AlphaMissense predicts likely benign (score 0.2692) — an in-silico prediction, not a clinical call.

CTSW p.Val203Ala

c.608T>C · VCV4657590

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.2692 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0274%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.2692	likely benign
REVEL	0.21	benign-leaning
SaProt	LLR -8.46	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 3.4	GERP 0.59, phastCons 1
Regional constraint	o/e 0.99	unconstrained · MANE · 3,760 bp · p 0.82 · regional, not allelic
Overall
CADD	22.0	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 0.0274% South Asian · 25/91,078 alleles

Filtering AF 0.019% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0163%

Overall 0.00167% 27/1,613,638 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0274%	3,643
Remaining individualsnot grpmax-eligible	0.0016%	62,482
European (non-Finnish)	8.47e-05%	1,179,979

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: CTSW
Protein: p.Val203Ala
Coding: c.608T>C
MANE Select: NM_001335
Type: single nucleotide variant
Location: chr11:65882678 (GRCh38)
Gene constraint: LOEUF 1.135 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.28
Residue 203: a disulfide bond

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

Similar variants

CTSW p.Ala109Gly Uncertain significance ★ ⚠ same type
CTSW p.Ala140Thr Uncertain significance ★ ⚠ same type
CTSW p.Ala28Val Uncertain significance ★ ⚠ same type
CTSW p.Ala41Asp Uncertain significance ★ ⚠ same type
CTSW p.Ala41Thr Uncertain significance ★ ⚠ same type
CTSW p.Ala71Thr Uncertain significance ★ ⚠ same type
CTSW p.Arg107Lys Uncertain significance ★ ⚠ same type
CTSW p.Arg135Gln Uncertain significance ★ ⚠ same type

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/ctsw-p-val203ala (accessed [today's date]).

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