Is TONSL p.Phe1173Cys (c.3518T>G) pathogenic?

TONSL p.Phe1173Cys (c.3518T>G) is classified Uncertain significance in TONSL (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-08-05). AlphaMissense: likely benign (0.1478); Rare (popmax 0.107%, afr); Associated with Inborn genetic diseases.

What condition is associated with TONSL p.Phe1173Cys (c.3518T>G)?

TONSL p.Phe1173Cys (c.3518T>G) is associated with Inborn genetic diseases (ClinVar).

How common is TONSL p.Phe1173Cys (c.3518T>G) in the general population?

TONSL p.Phe1173Cys (c.3518T>G) is rare (popmax 0.107%, afr) (gnomAD).

What do computational predictors say about TONSL p.Phe1173Cys (c.3518T>G)?

AlphaMissense predicts likely benign (score 0.1478) — an in-silico prediction, not a clinical call.

TONSL p.Phe1173Cys

c.3518T>G · rs143208435 · VCV1383136

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.1478 · ACMG-weighted

gnomAD v4.1

Rare

rare (popmax 0.107%, afr)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Inborn genetic diseases

Computational evidence

Protein change
AlphaMissense	0.1478	likely benign
REVEL	0.275	benign-leaning
SaProt	LLR -3.36	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 5.9	GERP 0.73, phastCons 1
Regional constraint	o/e 1.01	unconstrained · MANE · 15 kb · p 0.67 · regional, not allelic
Overall
CADD	21.8	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 0.107% African / African-American · 80/75,048 alleles

Filtering AF 0.0877% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0808%

Overall 0.0057% 92/1,613,408 alleles · rare exomes 40/1,461,098 · genomes 52/152,310 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.107%	938
Admixed American	0.0133%	7,501
Remaining individualsnot grpmax-eligible	0.0064%	15,625

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.Phe1173Cys
Coding: c.3518T>G
MANE Select: NM_013432
dbSNP: rs143208435
Type: single nucleotide variant
Location: chr8:144433629 (GRCh38)
Gene constraint: LOEUF 1.024 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 76.06 · 3 PDB
Residue 1173: 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.Phe1173Leu Uncertain significance ★ ⚠ 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-phe1173cys (accessed [today's date]).

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