Is TONSL p.Pro820Ser (c.2458C>T) pathogenic?

TONSL p.Pro820Ser (c.2458C>T) is classified Uncertain significance in TONSL (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-08-20). AlphaMissense: likely benign (0.0768); Ultra-rare (popmax 0.0497%, amr); Associated with Inborn genetic diseases.

What condition is associated with TONSL p.Pro820Ser (c.2458C>T)?

TONSL p.Pro820Ser (c.2458C>T) is associated with Inborn genetic diseases (ClinVar).

How common is TONSL p.Pro820Ser (c.2458C>T) in the general population?

TONSL p.Pro820Ser (c.2458C>T) is ultra-rare (popmax 0.0497%, amr) (gnomAD).

What do computational predictors say about TONSL p.Pro820Ser (c.2458C>T)?

AlphaMissense predicts likely benign (score 0.0768) — an in-silico prediction, not a clinical call.

TONSL p.Pro820Ser

c.2458C>T · rs539622862 · VCV1047672

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.0768 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0497%, amr)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Inborn genetic diseases

Computational evidence

Protein change
AlphaMissense	0.0768	likely benign
REVEL	0.019	moderately benign-leaning
SaProt	LLR -6.07	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · G>C here scores Δ0.40 · evaluated, not missing
Constraint at this position
Conservation	phyloP 0.16	GERP -3
Regional constraint	o/e 1.01	unconstrained · MANE · 15 kb · p 0.67 · regional, not allelic
Overall
CADD	1.194	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 0.0497% Admixed American · 28/56,356 alleles

Filtering AF 0.0352% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0304%

Overall 0.00328% 51/1,555,566 alleles · ultra-rare exomes 25/1,403,422 · genomes 26/152,144 · joint denominator

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.0497%	2,013
Remaining individualsnot grpmax-eligible	0.0133%	7,524
African / African-American	0.0027%	36,969
European (non-Finnish)	0.00113%	88,575

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.Pro820Ser
Coding: c.2458C>T
MANE Select: NM_013432
dbSNP: rs539622862
Type: single nucleotide variant
Location: chr8:144435975 (GRCh38)
Gene constraint: LOEUF 1.024 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 76.06 · 3 PDB
Residue 820: 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

Disease context

Inborn genetic diseases — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

TONSL p.Pro820= Likely benign ★ same residue
TONSL p.Ala1053Ser Uncertain significance ★★ ⚠ same condition
TONSL p.Ala1065Ser Uncertain significance ★★ ⚠ same condition
TONSL p.Ala1093Ser Uncertain significance ★★ ⚠ same condition
TONSL p.Ala1200Thr Uncertain significance ★★ ⚠ same condition
TONSL p.Ala215Thr Uncertain significance ★★ ⚠ same condition
TONSL p.Ala232Val Uncertain significance ★★ ⚠ same condition
TONSL p.Ala331Thr Uncertain significance ★★ ⚠ 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/tonsl-p-pro820ser (accessed [today's date]).

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