Is PIGS p.Gln401Ter (c.1201C>T) pathogenic?

PIGS p.Gln401Ter (c.1201C>T) is classified Uncertain significance in PIGS (ClinVar, Single submitter, 1 submitter; last evaluated 2015-12-21). Very rare (popmax 8.48e-05%, nfe).

How common is PIGS p.Gln401Ter (c.1201C>T) in the general population?

PIGS p.Gln401Ter (c.1201C>T) is very rare (popmax 8.48e-05%, nfe) (gnomAD).

PIGS p.Gln401Ter

c.1201C>T · rs1555534331 · VCV488852

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 8.48e-05%, nfe)

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 11 of 12
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · G>T here scores Δ0.20 · evaluated, not missing
Constraint at this position
Conservation	phyloP 7.5	GERP 1.8, phastCons 1
Overall
CADD	38.0	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 8.48e-05% European (non-Finnish) · 1/1,179,398 alleles

Overall 6.85e-05% 1/1,460,490 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: PIGS
Protein: p.Gln401Ter
Coding: c.1201C>T
MANE Select: NM_033198
dbSNP: rs1555534331
Type: single nucleotide variant
Location: chr17:28555042 (GRCh38)
Gene constraint: LOEUF 0.76 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 85.48 · 4 PDB
Residue 401: a UniProt-annotated variant site (in gpibd18; almost complete loss of function; when tested in pigs-knockout cells, mediates only very partial restoration of gpi-anchored protein expression at the cell surface; strong decrease in protein level, possibly due to nonsense-mediated mrna decay); an α-helix

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

Similar variants

PIGS p.Arg15Trp Uncertain significance ★★ ⚠ same type
PIGS p.Arg176Trp Uncertain significance ★★ ⚠ same type
PIGS p.Arg355Cys Uncertain significance ★★ ⚠ same type
PIGS p.Pro402Ser Uncertain significance ★★ ⚠ same type
PIGS p.Ser224Thr Uncertain significance ★★ ⚠ same type
PIGS p.Tyr522Cys Uncertain significance ★★ ⚠ same type
PIGS p.Val146Met Uncertain significance ★★ ⚠ same type
PIGS c.1080+15A>G Likely benign ★★ 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/pigs-p-gln401ter (accessed [today's date]).

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