Is ACSF3 p.Ala22= (c.66G>A) pathogenic?

ACSF3 p.Ala22= (c.66G>A) is classified Likely benign in ACSF3 (ClinVar, Single submitter, 2 submitters; last evaluated 2024-02-22). Ultra-rare (popmax 0.0133%, amr); Associated with combined malonic and methylmalonic acidemia.

What condition is associated with ACSF3 p.Ala22= (c.66G>A)?

ACSF3 p.Ala22= (c.66G>A) is associated with combined malonic and methylmalonic acidemia (ClinVar).

How common is ACSF3 p.Ala22= (c.66G>A) in the general population?

ACSF3 p.Ala22= (c.66G>A) is ultra-rare (popmax 0.0133%, amr) (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.Ala22=

c.66G>A · rs751461445 · VCV1089766

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.0133%, amr)

Conditions

combined malonic and methylmalonic acidemia

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 -1.3	GERP -3.2
Overall
CADD	6.738	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0133% Admixed American · 8/59,966 alleles

Filtering AF 0.00662% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00483%

Overall 0.00112% 18/1,606,320 alleles · ultra-rare

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.0133%	7,496
Remaining individualsnot grpmax-eligible	0.0016%	62,422
African / African-American	0.00133%	74,942
South Asian	0.0011%	91,066
European (non-Finnish)	0.000593%	168,545

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: ACSF3
Protein: p.Ala22=
Coding: c.66G>A
MANE Select: NM_001243279
dbSNP: rs751461445
Type: single nucleotide variant
Location: chr16:89100747 (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.Ala22Val Uncertain significance ★ ⚠ 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
ACSF3 c.666+1G>T 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-ala22 (accessed [today's date]).

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