12-102855311-CAC-GAG

Variant names:

• chr12-102855311-CAC-GAG
• NM_000277.3:c.529_531delGTGinsCTC
• PAH p.Val177Leu

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_ModerateO7_SupportingO8_Supporting

The NM_000277.3(PAH):c.529_531delGTGinsCTC (p.Val177Leu) variant causes a missense change. The gene PAH is a tumor suppressor gene (CancerMine: 1 TSG citations). Note: allele frequency estimates from gnomAD may be inaccurate for this variant type (MNP or indel longer than 3 bp) due to technology limitations. The variant is absent from the gnomAD population database at sites with sufficient sequencing coverage. The affected nucleotide is highly conserved across species (PhyloP 100-way vertebrate score: 9.32). 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.V177A: Likely_pathogenic (ClinVar VariationId 4710022, 1 star) This exact variant is curated in the UniProt human variants database as Uncertain Significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.32
• Publications: 0 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		Same AA change as established oncogenic variant (or germline P/LP in TSG) — Moderate (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: true | CIViC LOF: false | ClinVar diff-AA oncogenic: false | ClinVar diff-AA germline P/LP: true
	O7Mutational hotspot or critical domain		Supporting: cancerhotspots.org hit, critical domain, or missense neighbourhood hotspot; No cancerhotspots.org hit at this position; UniProt domain: 0 pathogenic, 0 benign.; ±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.529_531delGTGinsCTC p.Val177Leu	missense	N/A	Prot: NP_000268.1 UniProt:
	PAH NM_001354304.2		c.529_531delGTGinsCTC p.Val177Leu	missense	N/A	Prot: NP_001341233.1 UniProt:

PAH NM_000277.3

MANE Select

HGVSc / HGVSpc.529_531delGTGinsCTCp.Val177Leu

Exon rankN/A

missense

Prot: NP_000268.1UniProt: P00439

PAH NM_001354304.2

HGVSc / HGVSpc.529_531delGTGinsCTCp.Val177Leu

Exon rankN/A

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.529_531delGTGinsCTC p.Val177Leu	missense	N/A	Prot: ENSP00000448059.1 UniProt:
	PAH ENST00000549111.5	TSL:1	n.625_627delGTGinsCTC	non_coding_transcript_exon	Exon 6 of 6	Prot:
	PAH ENST00000906695.1		c.529_531delGTGinsCTC p.Val177Leu	missense	N/A	Prot: ENSP00000576754.1 UniProt:

PAH ENST00000553106.6

TSL:1MANE Select

HGVSc / HGVSpc.529_531delGTGinsCTCp.Val177Leu

Exon rankN/A

missense

Prot: ENSP00000448059.1UniProt: P00439

PAH ENST00000549111.5

TSL:1

HGVSc / HGVSpn.625_627delGTGinsCTC

Exon rankExon 6 of 6

non_coding_transcript_exon

Prot:

PAH ENST00000906695.1

HGVSc / HGVSpc.529_531delGTGinsCTCp.Val177Leu

Exon rankN/A

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 2 sources Large-scale international reference populations
GnomAD3 genomes	AF:	AC:	Hom:	AN:	Cov:33
GnomAD4 genome	AF:	AC:	Hom:	AN:	Cov:33

Showing 2 sources

ClinVar

Not reported in ClinVar

Computational Scores

Algorithm	Calibrated pred.	Score	Prediction
PhyloP100	Pathogenic	9.3

Showing 1 of 1 scores

Splicing Scores

No splicing scores have been computed for this variant.

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

hg19: chr12-103249089;

ACMG debug oncogenicity

ACGS debug oncogenicity

ACMG debug germline

Submit to ClinVar