Is FAH p.Val166= (c.498C>T) pathogenic?

FAH p.Val166= (c.498C>T) is classified Likely benign in FAH (ClinVar, Single submitter, 1 submitter; last evaluated 2025-11-24). Ultra-rare (popmax 0.0164%, mid); Associated with tyrosinemia type I.

What condition is associated with FAH p.Val166= (c.498C>T)?

FAH p.Val166= (c.498C>T) is associated with tyrosinemia type I (ClinVar).

How common is FAH p.Val166= (c.498C>T) in the general population?

FAH p.Val166= (c.498C>T) is ultra-rare (popmax 0.0164%, mid) (gnomAD).

How is Tyrosinemia type 1 inherited?

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

FAH p.Val166=

c.498C>T · rs143712599 · VCV1659994

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0164%, mid)

Conditions

tyrosinemia type I

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 -8.9	GERP -3
Overall
CADD	0.452	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0164% Middle Eastern · 1/6,084 alleles

Filtering AF 0.0021% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00136%

Overall 0.00105% 17/1,614,044 alleles · ultra-rare exomes 16/1,461,862 · genomes 1/152,182 · joint denominator

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0164%	6,084
South Asian	0.00549%	18,214
East Asian	0.00223%	44,880
Remaining individualsnot grpmax-eligible	0.0016%	62,490
European (non-Finnish)	0.000763%	131,116

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: FAH
Protein: p.Val166=
Coding: c.498C>T
MANE Select: NM_000137
dbSNP: rs143712599
Type: single nucleotide variant
Location: chr15:80168094 (GRCh38)
Gene constraint: LOEUF 1.067 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 98.06 · 8 PDB
Residue 166: a UniProt-annotated variant site (in tyrsn1)

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

Disease context

tyrosinemia type I — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Tyrosinemia type 1 (Orphanet):

Inheritance: Autosomal recessive
Onset: All ages
Prevalence: 1-9 / 1 000 000 (Worldwide)

Similar variants

FAH p.Val166Gly Likely pathogenic ★★ same residue
FAH p.Val166Leu Uncertain significance ★ ⚠ same residue
FAH c.1062+5G>A Pathogenic/Likely pathogenic ★★ same condition
FAH c.1180+1G>A Pathogenic ★★ same condition
FAH c.192+1G>A Likely pathogenic ★★ same condition
FAH c.192+1G>T Pathogenic/Likely pathogenic ★★ same condition
FAH c.193-2A>G Likely pathogenic ★★ same condition
FAH c.314+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/fah-p-val166 (accessed [today's date]).

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