chr12-102855316-G-C

Variant names:

• chr12-102855316-G-C
• rs199475575
• NM_000277.3:c.526C>G
• PAH p.Arg176Gly

GermlineCancer (beta)

Variant summary

Our verdict is Likely pathogenic.

+6 Likely Pathogenic

-7

-6

-1

0

+5

+6

+9

+10

BenignB

Likely BenignLB

UncertainVUS

Likely PathogenicLP

PathogenicP

The variant received 6 classification points (ACGS-UK Somatic Oncogenicity v2025). O3_ModerateO5_SupportingO7_ModerateO8_Supporting

The NM_000277.3(PAH):c.526C>G (p.Arg176Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The gene PAH is a tumor suppressor gene (CancerMine: 1 TSG citations). The variant is absent from the gnomAD population database at sites with sufficient sequencing coverage. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. A different missense at the same amino acid position has been reported as Pathogenic/Likely Pathogenic in ClinVar: p.R176P: Pathogenic (ClinVar VariationId 102725, 1 star) Other variants at the same amino acid position have been reported in ClinVar (not pathogenic): p.R176= (synonymous): Likely_benign (ClinVar VariationId 2840878, 1 star) The variant has been observed in cBioPortal in 2 samples across 1 study and 1 cancer type; somatic enrichment level: NONE (Observed in at most one deduplicated cBioPortal case.).

• Frequency: Genomes: not found (cov: 33)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.975
• Publications: 45 publications found

Genes affected

PAH (HGNC:8582): (phenylalanine hydroxylase) This gene encodes a member of the biopterin-dependent aromatic amino acid hydroxylase protein family. The encoded phenylalanine hydroxylase enzyme hydroxylates phenylalanine to tyrosine and is the rate-limiting step in phenylalanine catabolism. Deficiency of this enzyme activity results in the autosomal recessive disorder phenylketonuria. [provided by RefSeq, Aug 2017]

PAH Gene-Disease associations (from GenCC):

• classic phenylketonuria

  Inheritance: AR Classification: DEFINITIVE Submitted by: Natera
• phenylketonuria

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, ClinGen, Labcorp Genetics (formerly Invitae), Myriad Women's Health
• maternal phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mild hyperphenylalaninemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• tetrahydrobiopterin-responsive hyperphenylalaninemia/phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Classification according to ACGS-UK Somatic Oncogenicity v2025

Specifications for PAH are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Classification was made for transcript:

Our verdict: Likely_pathogenic. The variant received 6 points.

Apply	Criterion Code & Title / Strength	Strength	Rationale / Clinical Context
	O3Absent or very rare in population		Absent or extremely rare in gnomAD (AC ≤ 2) — O3 moderate; GnomAD: AF = absent, AC = 0 — absent/extremely rare (O3 moderate [+2])
	O5Same location/impact as known oncogenic		Different AA at same residue with oncogenic evidence (or germline P/LP in TSG), or same AA change SCI Tier II Potential — Supporting (O5); ClinVar same-AA oncogenic/T1: false | ClinVar same-AA SCI tier: — | CGI same-AA oncogenic: false | TSG: true | ClinVar same-AA germline P/LP: false | CIViC LOF: false | ClinVar diff-AA oncogenic: false | ClinVar diff-AA germline P/LP: true
	O7Mutational hotspot or critical domain		Moderate: ≥10 same AA change, or strong functional domain signal; No cancerhotspots.org hit at this position; UniProt domain: 7 pathogenic, 0 benign (OR vs. background: 75.0).; ±8 AA neighbourhood: 35 pathogenic, 0 benign (OR vs. background: 355.0); Variant does not impact splicing — splice-hotspot path not applicable
	O8Missense constraint in gene or region		Missense in gene/domain constrained for missense variation where missense is common disease mechanism (O8 supporting); Gene/disease mechanism: missense is a common mechanism of oncogenesis; gnomAD missense Z-score: -0.00 (threshold ≥3.09 for constraint); Domain-level constraint: variant is in a critically constrained functional domain (IS_AT_CRITICAL_DOMAIN)

Variant Effect in Transcripts

Automated classification analysis was done for transcript: NM_000277.3. You can select a different transcript below to see updated classification assignments.

RefSeq Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	PAH NM_000277.3	MANE Select	c.526C>G p.Arg176Gly	missense	Exon 6 of 13	Prot: NP_000268.1 UniProt:
	PAH NM_001354304.2		c.526C>G p.Arg176Gly	missense	Exon 7 of 14	Prot: NP_001341233.1 UniProt:

PAH NM_000277.3

MANE Select

HGVSc / HGVSpc.526C>Gp.Arg176Gly

Exon rankExon 6 of 13

missense

Prot: NP_000268.1UniProt: P00439

PAH NM_001354304.2

HGVSc / HGVSpc.526C>Gp.Arg176Gly

Exon rankExon 7 of 14

missense

Prot: NP_001341233.1UniProt: P00439

Ensembl Transcripts

Sel.	Gene / Transcript	Tags	HGVSc / HGVSp	Effect	Exon rank	Protein / UniProt
	PAH ENST00000553106.6	TSL:1MANE Select	c.526C>G p.Arg176Gly	missense	Exon 6 of 13	Prot: ENSP00000448059.1 UniProt:
	PAH ENST00000549111.5	TSL:1	n.622C>G	non_coding_transcript_exon	Exon 6 of 6	Prot:
	PAH ENST00000906695.1		c.526C>G p.Arg176Gly	missense	Exon 6 of 14	Prot: ENSP00000576754.1 UniProt:

PAH ENST00000553106.6

TSL:1MANE Select

HGVSc / HGVSpc.526C>Gp.Arg176Gly

Exon rankExon 6 of 13

missense

Prot: ENSP00000448059.1UniProt: P00439

PAH ENST00000549111.5

TSL:1

HGVSc / HGVSpn.622C>G

Exon rankExon 6 of 6

non_coding_transcript_exon

Prot:

PAH ENST00000906695.1

HGVSc / HGVSpc.526C>Gp.Arg176Gly

Exon rankExon 6 of 14

missense

Prot: ENSP00000576754.1UniProt: A0ACI8RXH2

Frequencies

Allele frequencies (AF), counts (AC/AN), homozygotes and coverage

Common (AF > 0.05 / Hom > 5)

Rare (AF ≤ 0.0001 / Hom ≤ 1)

Source / population	AF	AC	Hom	AN	Coverage
Global population databases 3 sources Large-scale international reference populations
GnomAD3 genomes	AF:	AC:	Hom:	AN:	Cov:33
GnomAD4 exome	AF:	AC:	Hom:	AN:	Cov:34
GnomAD4 genome	AF:	AC:	Hom:	AN:	Cov:33

Showing 3 sources

ClinVar

Not reported in ClinVar

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
AlphaGenome AVI	Pathogenic	21
AlphaMissense	Benign	0.24
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D
Eigen	Benign	0.16
Eigen_PC	Benign	0.10
FATHMM_MKL	Benign	0.41	N
FuncVEP CTI	Benign	0.15
GPN-Star LLR	N/A	-6.0
GPN-Star score	N/A	6.0
LIST_S2	Benign	0.84	T
M_CAP	Pathogenic	0.44	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.1	D
Mutation Taster	N/A	45/55	disease causing
MutationAssessor	Pathogenic	3.9	H
PhyloP100	Benign	0.97
popEVE	Benign	-3.2
PrimateAI	Benign	0.25	T
PROVEAN	Pathogenic	-5.1	D
RBP_binding_hub_radar	N/A	0.0
RBP_regulation_power_radar	N/A	1.1
REVEL	Uncertain	0.62
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.021	D
Varity_R	N/A	0.73
VESM-3B	Benign	-10

Showing 30 of 30 scores

Splicing Scores

Algorithm	Calibrated pred.	Score	Prediction
Pangolin (max)	Benign	0.010
SpliceAI score (max)	Benign	0.0	Details are displayed if max score is > 0.2

Showing 2 of 2 scores

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

MaveDB functional evidence

MaveDB is a public repository of laboratory assays that test the effect of thousands of variants at once — treat this as supporting research data and interpret it with great caution; it is not a clinical classification.

No MaveDB functional evidence found for this variant.

Other links and lift over

dbSNP: rs199475575;

hg19: chr12-103249094;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar