Is ACSF3 p.Ser548Ter (c.1643C>A) pathogenic?

ACSF3 p.Ser548Ter (c.1643C>A) is classified Pathogenic in ACSF3 (ClinVar, Single submitter, 1 submitter; last evaluated 2020-12-19). Absent from gnomAD v4.1; Associated with combined malonic and methylmalonic acidemia.

What condition is associated with ACSF3 p.Ser548Ter (c.1643C>A)?

ACSF3 p.Ser548Ter (c.1643C>A) is associated with combined malonic and methylmalonic acidemia (ClinVar).

How common is ACSF3 p.Ser548Ter (c.1643C>A) in the general population?

ACSF3 p.Ser548Ter (c.1643C>A) is absent from gnomAD v4.1 (gnomAD).

How is Combined malonic and methylmalonic acidemia inherited?

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

ACSF3 p.Ser548Ter

c.1643C>A · rs139520739 · VCV1396014

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

combined malonic and methylmalonic acidemia

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	escapes	premature termination codon in the last exon (11 of 11) — the truncated protein is likely expressed. PVS1 input, not an applied code
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.4	GERP 1.2, 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

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: ACSF3
Protein: p.Ser548Ter
Coding: c.1643C>A
MANE Select: NM_001243279
dbSNP: rs139520739
Type: single nucleotide variant
Location: chr16:89154119 (GRCh38)
Gene constraint: LOEUF 1.715 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 86.58

Full ACSF3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

combined malonic and methylmalonic acidemia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Combined malonic and methylmalonic acidemia (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive
Onset: All ages
Prevalence: 1-9 / 100 000 (United States)

Similar variants

ACSF3 p.Ser548Leu Uncertain significance ★★ ⚠ same residue
ACSF3 p.Ser548= Likely benign ★ same residue
ACSF3 c.1366+1G>A Likely pathogenic ★★ same condition
ACSF3 c.1501+1G>A Likely pathogenic ★★ same condition
ACSF3 c.1501+1G>T Likely pathogenic ★★ same condition
ACSF3 c.1502-2A>G Pathogenic/Likely pathogenic ★★ same condition
ACSF3 c.1613+1G>A Pathogenic/Likely pathogenic ★★ same condition
ACSF3 c.666+1G>A 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/acsf3-p-ser548ter (accessed [today's date]).

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