Is CTNS p.Tyr100Ter (c.300T>A) pathogenic?

CTNS p.Tyr100Ter (c.300T>A) is classified Pathogenic/Likely pathogenic in CTNS (ClinVar, Multiple submitters, 2 submitters; last evaluated 2023-01-20). Very rare (popmax 0.00446%, eas); Associated with Inborn genetic diseases.

What condition is associated with CTNS p.Tyr100Ter (c.300T>A)?

CTNS p.Tyr100Ter (c.300T>A) is associated with Inborn genetic diseases, ocular cystinosis, juvenile nephropathic cystinosis (ClinVar).

How common is CTNS p.Tyr100Ter (c.300T>A) in the general population?

CTNS p.Tyr100Ter (c.300T>A) is very rare (popmax 0.00446%, eas) (gnomAD).

CTNS p.Tyr100Ter

c.300T>A · rs376042415 · VCV984078

Pathogenic/Likely pathogenic Multiple submitters

Classification

Pathogenic/Likely pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.00446%, eas)

Conditions

Inborn genetic diseases

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function
NMD	predicted	premature termination codon in exon 6 of 12
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · T>G here scores Δ0.20 · evaluated, not missing
Constraint at this position
Conservation	phyloP -0.95	GERP -2.8, phastCons 0.001
Overall
CADD	35.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00446% East Asian · 2/44,880 alleles

Filtering AF 0.000739% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000276%

Overall 0.000137% 2/1,461,834 alleles · very rare

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: CTNS
Protein: p.Tyr100Ter
Coding: c.300T>A
MANE Select: NM_004937
dbSNP: rs376042415
Type: single nucleotide variant
Location: chr17:3655072 (GRCh38)
Gene constraint: LOEUF 0.754 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 89.27 · 6 PDB
Residue 100: a β-strand

Full CTNS 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

Also linked: ocular cystinosis juvenile nephropathic cystinosis cystinosis

Similar variants

CTNS p.Tyr100= Likely benign ★ same residue
CTNS c.140+1G>T Pathogenic/Likely pathogenic ★★ same condition
CTNS c.140+2T>C Pathogenic/Likely pathogenic ★★ same condition
CTNS c.141-1G>A Pathogenic/Likely pathogenic ★★ same condition
CTNS c.141-24T>C Pathogenic ★★ same condition
CTNS c.225+3A>T Pathogenic/Likely pathogenic ★★ same condition
CTNS c.225+5G>A Likely pathogenic ★★ same condition
CTNS c.61+2T>C 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/ctns-p-tyr100ter (accessed [today's date]).

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