Is PEX1 p.Ser278Ter (c.833C>G) pathogenic?

PEX1 p.Ser278Ter (c.833C>G) is classified Pathogenic in PEX1 (ClinVar, Single submitter, 1 submitter; last evaluated 2023-09-19). Absent from gnomAD v4.1; Associated with Zellweger spectrum disorders.

What condition is associated with PEX1 p.Ser278Ter (c.833C>G)?

PEX1 p.Ser278Ter (c.833C>G) is associated with Zellweger spectrum disorders (ClinVar).

How common is PEX1 p.Ser278Ter (c.833C>G) in the general population?

PEX1 p.Ser278Ter (c.833C>G) is absent from gnomAD v4.1 (gnomAD).

How is Zellweger syndrome inherited?

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

PEX1 p.Ser278Ter

c.833C>G · rs2484703148 · VCV2040673

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

Zellweger spectrum disorders

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 5 of 24
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 9.8	GERP 2.1, phastCons 1
Overall
CADD	36.0	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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: PEX1
Protein: p.Ser278Ter
Coding: c.833C>G
MANE Select: NM_000466
dbSNP: rs2484703148
Type: single nucleotide variant
Location: chr7:92517682 (GRCh38)
Gene constraint: LOEUF 0.746 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 67.19

Full PEX1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Zellweger spectrum disorders — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Zellweger syndrome (Orphanet):

Inheritance: Autosomal recessive
Onset: Neonatal

Similar variants

PEX1 p.Ser278= Likely benign ★ same residue
PEX1 p.Ser278fs Pathogenic/Likely pathogenic ★★ same residue
PEX1 c.1239+1G>T Pathogenic ★★ same condition
PEX1 c.130-1G>T Pathogenic/Likely pathogenic ★★ same condition
PEX1 c.130-2A>G Pathogenic/Likely pathogenic ★★ same condition
PEX1 c.130-2A>T Pathogenic/Likely pathogenic ★★ same condition
PEX1 c.1483+1G>A Pathogenic ★★ same condition
PEX1 c.1587+1G>A 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/pex1-p-ser278ter (accessed [today's date]).

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