Is CA5A p.Ser141fs (c.419dup) pathogenic?

CA5A p.Ser141fs (c.419dup) is classified Pathogenic in CA5A (ClinVar, Single submitter, 1 submitter; last evaluated 2024-03-20). Very rare (popmax 8.48e-05%, nfe); Associated with hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency.

What condition is associated with CA5A p.Ser141fs (c.419dup)?

CA5A p.Ser141fs (c.419dup) is associated with hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency (ClinVar).

How common is CA5A p.Ser141fs (c.419dup) in the general population?

CA5A p.Ser141fs (c.419dup) is very rare (popmax 8.48e-05%, nfe) (gnomAD).

CA5A p.Ser141fs

Q: How is Hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency inherited?

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

c.419dup · VCV3645507

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

frameshift

predicted LoF

gnomAD v4.1

Rare

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

Conditions

hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	frameshift	predicted loss-of-function
NMD	predicted	premature termination codon in exon 3 of 7
Splicing
SpliceAI	—	not assessed · substitutions only
Constraint at this position
Conservation	phyloP 3.6	GERP 0.89, phastCons 1
Region caveats
Repeat context	seg dup	· reads may not map uniquely · confidence, not pathogenicity

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) · 1/1,178,782 alleles

Overall 6.85e-05% 1/1,460,468 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: CA5A
Protein: p.Ser141fs
Coding: c.419dup
MANE Select: NM_001739
Type: Duplication
Location: chr16:87904825 (GRCh38)
Gene constraint: LOEUF 1.257 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.38
Residue 141: the alpha-carbonic anhydrase domain

Full CA5A gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood, Infancy, Neonatal

Similar variants

CA5A p.Arg32Ter Pathogenic ★★ same condition
CA5A p.Glu241Lys Pathogenic/Likely pathogenic ★★ same condition
CA5A p.Ala149Thr Uncertain significance ★★ ⚠ same condition
CA5A p.Ala208Val Uncertain significance ★★ ⚠ same condition
CA5A p.Ala261Val Uncertain significance ★★ ⚠ same condition
CA5A p.Arg26His Uncertain significance ★★ ⚠ same condition
CA5A p.Asp216Ala Uncertain significance ★★ ⚠ same condition
CA5A p.Gln79Glu Uncertain significance ★★ ⚠ 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/ca5a-p-ser141fs (accessed [today's date]).

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