Is CA5A p.Val171= (c.513C>T) pathogenic?

CA5A p.Val171= (c.513C>T) is classified Likely benign in CA5A (ClinVar, Single submitter, 1 submitter; last evaluated 2024-10-26). Ultra-rare (popmax 0.01%, amr); Associated with hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency.

What condition is associated with CA5A p.Val171= (c.513C>T)?

CA5A p.Val171= (c.513C>T) is associated with hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency (ClinVar).

How common is CA5A p.Val171= (c.513C>T) in the general population?

CA5A p.Val171= (c.513C>T) is ultra-rare (popmax 0.01%, amr) (gnomAD).

CA5A p.Val171=

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.513C>T · rs769040032 · VCV1981637

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.01%, amr)

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.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -10	GERP -4
Overall
CADD	0.051	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.01% Admixed American · 6/59,960 alleles

Filtering AF 0.00429% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00295%

Overall 0.00124% 20/1,612,106 alleles · ultra-rare

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.01%	9,993
East Asian	0.00668%	14,965
Finnishnot grpmax-eligible	0.00156%	63,980
European (non-Finnish)	0.000849%	117,837

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.Val171=
Coding: c.513C>T
MANE Select: NM_001739
dbSNP: rs769040032
Type: single nucleotide variant
Location: chr16:87902467 (GRCh38)
Gene constraint: LOEUF 1.257 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.38
Residue 171: 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.Val171Ala Uncertain significance ★ ⚠ same residue
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

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-val171 (accessed [today's date]).

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