Is TONSL p.Arg849Cys (c.2545C>T) pathogenic?

TONSL p.Arg849Cys (c.2545C>T) is classified Uncertain significance in TONSL (ClinVar, Single submitter, 1 submitter; last evaluated 2025-02-06). AlphaMissense: likely benign (0.095); Ultra-rare (popmax 0.0202%, eas).

How common is TONSL p.Arg849Cys (c.2545C>T) in the general population?

TONSL p.Arg849Cys (c.2545C>T) is ultra-rare (popmax 0.0202%, eas) (gnomAD).

What do computational predictors say about TONSL p.Arg849Cys (c.2545C>T)?

AlphaMissense predicts likely benign (score 0.095) — an in-silico prediction, not a clinical call.

TONSL p.Arg849Cys

c.2545C>T · rs371172887 · VCV1470850

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.095 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0202%, eas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.095	likely benign
REVEL	0.05	moderately benign-leaning
SaProt	LLR -8.86	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 0.86	GERP -2.5, phastCons 0.67
Regional constraint	o/e 1.01	unconstrained · MANE · 15 kb · p 0.67 · regional, not allelic
Overall
CADD	21.3	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 0.0202% East Asian · 9/44,480 alleles

Filtering AF 0.0105% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00785%

Overall 0.00144% 23/1,598,574 alleles · ultra-rare exomes 18/1,446,238 · genomes 5/152,336 · joint denominator

Ancestry group	Frequency	1 in
East Asiangrpmax	0.0202%	4,942
Middle Eastern	0.0166%	6,010
South Asian	0.00331%	30,189
Remaining individualsnot grpmax-eligible	0.00324%	30,854
European (non-Finnish)	0.000684%	146,148

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: TONSL
Protein: p.Arg849Cys
Coding: c.2545C>T
MANE Select: NM_013432
dbSNP: rs371172887
Type: single nucleotide variant
Location: chr8:144435888 (GRCh38)
Gene constraint: LOEUF 1.024 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 76.06 · 3 PDB
Residue 849: the 'disordered' region; a UniProt-annotated variant site (in semdsp; disease phenotype includes immunologic and hematologic abnormalities); a UniProt-annotated variant site (in semdsp); a UniProt-annotated variant site (in semdsp; disease phenotype includes primary aphakia and absent pupils)

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

Similar variants

TONSL p.Arg849His Conflicting classifications of pathogenicity ★ ⚠ same residue
TONSL c.1891-1G>C Pathogenic/Likely pathogenic ★★ same type
TONSL p.Arg875Ter Pathogenic/Likely pathogenic ★★ same type
TONSL p.Arg934Trp Pathogenic ★★ ⚠ same type
TONSL p.Gln177Ter Pathogenic/Likely pathogenic ★★ same type
TONSL p.Gln511Ter Pathogenic/Likely pathogenic ★★ same type
TONSL p.Glu487Lys Pathogenic/Likely pathogenic ★★ ⚠ same type
TONSL c.2775+5G>T 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/tonsl-p-arg849cys (accessed [today's date]).

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