rs78655458

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PP4_ModeratePM2PP3PM3PS3

This summary comes from the ClinGen Evidence Repository: The c.829T>G (p.Tyr277Asp) variant in PAH has been reported in 2 individuals with Classic PKU (BH4 deficiency excluded). (PP4_Moderate; PMID:8268925; PMID:23500595). This variant has an extremely low allele frequency (1/121400) in ExAC (PM2; http://exac.broadinstitute.org). This variant has 0% enzyme activity (PS3; http://www.biopku.org/centralStore/biopku/PAH%20activity.pdf). This variant was detected in trans with L48S (Pathogenic in ClinVar) (PM3; PMID:23500595). Computational prediction tools and conservation analysis suggest that the c.829T>G variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PP4_Moderate, PS3 LINK:https://erepo.genome.network/evrepo/ui/classification/CA251534/MONDO:0009861/006

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

PAH
NM_000277.3 missense

Scores

14
4
1

Clinical Significance

Pathogenic reviewed by expert panel P:13O:1

Conservation

PhyloP100: 7.52
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PS3
For more information check the summary or visit ClinGen Evidence Repository.
PM2
For more information check the summary or visit ClinGen Evidence Repository.
PM3
For more information check the summary or visit ClinGen Evidence Repository.
PP3
For more information check the summary or visit ClinGen Evidence Repository.
PP4
For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PAHNM_000277.3 linkc.829T>G p.Tyr277Asp missense_variant Exon 7 of 13 ENST00000553106.6 NP_000268.1 P00439A0A024RBG4
PAHNM_001354304.2 linkc.829T>G p.Tyr277Asp missense_variant Exon 8 of 14 NP_001341233.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PAHENST00000553106.6 linkc.829T>G p.Tyr277Asp missense_variant Exon 7 of 13 1 NM_000277.3 ENSP00000448059.1 P00439
PAHENST00000307000.7 linkc.814T>G p.Tyr272Asp missense_variant Exon 8 of 14 5 ENSP00000303500.2 J3KND8
PAHENST00000549247.6 linkn.588T>G non_coding_transcript_exon_variant Exon 1 of 6 2
PAHENST00000635477.1 linkc.-12T>G upstream_gene_variant 5 ENSP00000489230.1 A0A0U1RQY4

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000159
AC:
4
AN:
251352
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135842
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000376
AC:
55
AN:
1461776
Hom.:
0
Cov.:
31
AF XY:
0.0000344
AC XY:
25
AN XY:
727196
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000459
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74348
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000710
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:13Other:1
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Phenylketonuria Pathogenic:9
Nov 10, 2021
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 05, 2018
ClinGen PAH Variant Curation Expert Panel
Significance: Pathogenic
Review Status: reviewed by expert panel
Collection Method: curation

The c.829T>G (p.Tyr277Asp) variant in PAH has been reported in 2 individuals with Classic PKU (BH4 deficiency excluded). (PP4_Moderate; PMID: 8268925; PMID: 23500595). This variant has an extremely low allele frequency (1/121400) in ExAC (PM2; http://exac.broadinstitute.org). This variant has 0% enzyme activity (PS3; http://www.biopku.org/centralStore/biopku/PAH%20activity.pdf). This variant was detected in trans with L48S (Pathogenic in ClinVar) (PM3; PMID: 23500595). Computational prediction tools and conservation analysis suggest that the c.829T>G variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PP4_Moderate, PS3 -

Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 05, 2017
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: The PAH c.829T>G (p.Tyr277Asp) variant involves the alteration of a conserved nucleotide located in the Aromatic amino acid hydroxylase, C-terminal domain (InterPro). 5/5 in silico tools predict a damaging outcome for this variant. This variant was found in 1/121400 control chromosomes at a frequency of 0.0000082, which does not exceed the estimated maximal expected allele frequency of a pathogenic PAH variant (0.0079057). The variant has been reported in numerous affected individuals in the literature in the homozygous and compound heterozygous state. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Sep 16, 2020
Natera, Inc.
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Jan 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 277 of the PAH protein (p.Tyr277Asp). This variant is present in population databases (rs78655458, gnomAD 0.003%). This missense change has been observed in individual(s) with hyperphenylalaninemia (PMID: 2035532, 8268925, 8632937, 12173030, 12655546, 23500595, 26666653). This variant is also known as c.754C>T. ClinVar contains an entry for this variant (Variation ID: 603). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt PAH protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects PAH function (PMID: 12655546). For these reasons, this variant has been classified as Pathogenic. -

Jun 01, 1991
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Nov 06, 2018
Counsyl
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Feb 06, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Pathogenic:3Other:1
Oct 05, 2020
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Reported previously in association with both classic and moderate phenylketonuria (Labrune et al., 1991; Couce et al., 2013; Aldamiz-Echevarria et al., 2016); Functional studies in COS cells showed no residual enzyme activity compared to wild-type (Pey et al., 2003); Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Response to BH4 therapy is inconsistent (Couce et al., 2013; Jeannesson-Thivisol et al., 2015; Aldamiz-Echevarria et al., 2016); This variant is associated with the following publications: (PMID: 18346471, 27413125, 12655546, 21953985, 25882749, 23500595, 27121329, 26666653, 2035532, 30037505, 31980526, 31589614, 32668217) -

-
DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE
Significance: not provided
Review Status: no classification provided
Collection Method: literature only

- -

Oct 05, 2016
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 15, 2014
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

PAH-related disorder Pathogenic:1
Apr 07, 2024
PreventionGenetics, part of Exact Sciences
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

The PAH c.829T>G variant is predicted to result in the amino acid substitution p.Tyr277Asp. This variant has been reported, in homozygous state or in combination with a second pathogenic PAH variant, as causative for moderate or classic phenylketonuria (Pey et al. 2003. PubMed ID: 12655546; Sarkissian et al. 2012. PubMed ID: 23430918; Couce et al. 2013. PubMed ID: 23500595; Jeannesson-Thivisol et al. 2015. PubMed ID: 26666653; Table S1, Aldámiz-Echevarría et al. 2015. PubMed ID: 25882749; Hillert et al. 2020. PubMed ID: 32668217). It has been reported that the p.Tyr277 amino acid is near the active site of the enzyme, and functional studies of the p.Tyr277Asp variant have shown that this amino acid change completely abrogates the activity of the PAH enzyme (Pey et al. 2003. PubMed ID: 12655546; Shi et al. 2012. PubMed ID: 21953985). This variant has been interpreted as pathogenic by multiple outside laboratories, as well as the ClinGen PAH Variant Curation Expert Panel (https://www.ncbi.nlm.nih.gov/clinvar/variation/603/). This variant is reported in 0.0031% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
1.0
D;D
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.94
D;D
M_CAP
Pathogenic
0.73
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Pathogenic
4.8
H;.
PrimateAI
Pathogenic
0.85
D
PROVEAN
Pathogenic
-9.6
D;D
REVEL
Pathogenic
0.95
Sift
Uncertain
0.0050
D;D
Sift4G
Uncertain
0.015
D;D
Polyphen
1.0
D;.
Vest4
0.96
MVP
0.99
MPC
0.29
ClinPred
1.0
D
GERP RS
4.6
Varity_R
0.94
gMVP
0.99

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs78655458; hg19: chr12-103246606; API