Is CPS1 p.Tyr309= (c.927C>T) pathogenic?

CPS1 p.Tyr309= (c.927C>T) is classified Likely benign in CPS1 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2023-07-16). Very rare (popmax 6.85e-05%); Associated with carbamoyl phosphate synthetase I deficiency disease.

What condition is associated with CPS1 p.Tyr309= (c.927C>T)?

CPS1 p.Tyr309= (c.927C>T) is associated with carbamoyl phosphate synthetase I deficiency disease (ClinVar).

How common is CPS1 p.Tyr309= (c.927C>T) in the general population?

CPS1 p.Tyr309= (c.927C>T) is very rare (popmax 6.85e-05%) (gnomAD).

How is Carbamoyl-phosphate synthetase 1 deficiency inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

CPS1 p.Tyr309=

c.927C>T · rs1553511083 · VCV511480

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 6.85e-05%)

Conditions

carbamoyl phosphate synthetase I deficiency disease

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 1.7	GERP 1.2, phastCons 1
Overall
CADD	11.07	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 6.85e-05%

Overall 6.85e-05% 1/1,459,220 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: CPS1
Protein: p.Tyr309=
Coding: c.927C>T
MANE Select: NM_001875
dbSNP: rs1553511083
Type: single nucleotide variant
Location: chr2:210590886 (GRCh38)
Gene constraint: LOEUF 0.764 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 93.80 · 14 PDB
Residue 309: the glutamine amidotransferase type-1 domain; a β-strand

Full CPS1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

carbamoyl phosphate synthetase I deficiency disease — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Carbamoyl-phosphate synthetase 1 deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: All ages

Similar variants

CPS1 p.Tyr309Ter Pathogenic ★ same residue
CPS1 c.1086+1G>A Likely pathogenic ★★ same condition
CPS1 c.1087-1G>T Pathogenic/Likely pathogenic ★★ same condition
CPS1 c.1165-2A>G Likely pathogenic ★★ same condition
CPS1 c.1263+5G>C Pathogenic/Likely pathogenic ★★ same condition
CPS1 c.1549+1G>A Pathogenic/Likely pathogenic ★★ same condition
CPS1 c.1549+1G>T Pathogenic/Likely pathogenic ★★ same condition
CPS1 c.1837-8A>G Pathogenic/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/cps1-p-tyr309 (accessed [today's date]).

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