Send feedback

PAH p.Val262=

c.786C>T · rs776860902 · VCV883189

Uncertain significance Expert panel
Classification
Uncertain significance
ClinVar
Review
Expert panel ★★★☆
ClinVar · 4 submitters
gnomAD v4.1
Rare
very rare (popmax 0.000254%, nfe)
Conditions
1
phenylketonuria

ClinGen expert panel — Phenylketonuria VCEP

Uncertain Significance for phenylketonuria. Applied ACMG criteria (verbatim):

PM2_Supporting

Curation rationale (ClinGen, verbatim)

The NM_000277.3:c.786C>T in PAH is a synonymous (silent) variant (p.Val262=) that is not predicted to impact splicing. To our knowledge, this variant has not been reported in the literature and results of functional studies are unavailable. This variant is absent in gnomAD v2.1.1 (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID: 883189, 1 star review status) with two submitters classifying the variant as a variant of uncertain significance and one submitter classifying the variant as likely benign. In summary, this variant meets the criteria to be classified as a variant of uncertain significance for PAH deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen PAH Variant Curation Expert Panel (Specifications Version 2.0): PM2_Supporting.

ClinGen Evidence Repository → · reported verbatim, not re-tallied by Sugi Variant.

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
ConservationphyloP 2.5GERP -0.8, phastCons 1
Overall
CADD7.897PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes
Grpmax group 0.000254% European (non-Finnish) · 3/1,180,008 alleles
Filtering AF 6.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.9e-05%
Overall 0.000248% 4/1,613,998 alleles · very rare exomes 3/1,461,846 · genomes 1/152,152 · joint denominator
Ancestry group Frequency 1 in
Remaining individualsnot grpmax-eligible 0.0016% 62,482
European (non-Finnish)grpmax 0.000254% 393,335

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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
PAH
Protein
p.Val262=
Coding
c.786C>T
MANE Select
NM_000277
dbSNP
rs776860902
Type
single nucleotide variant
Location
chr12:102852871 (GRCh38)
Gene constraint
LOEUF 1.265 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure
AlphaFold pLDDT 89.04 · 21 PDB
Residue 262
a β-strand
Full PAH gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

phenylketonuria — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Phenylketonuria (Orphanet):

Inheritance
Autosomal recessive
Onset
Infancy
Prevalence
1-9 / 100 000 (France)

Similar variants

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/pah-p-val262 (accessed [today's date]).

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