chr12-102840492-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PP4_ModeratePP3PS3PM3_Strong

This summary comes from the ClinGen Evidence Repository: PAH-specific ACMG/AMP criteria applied: PM3_Strong: In trans with R408W, IVS4-1G>A, R241C (ClinGen, P) (PMID:1312992; PMID:14722928); PP3: ; PS3: Mutant enzyme activity of 46% in BioPKU (PMID:9860305); PP4_Moderate: ~830 uml/L w/o BH4 deficiency & 823 umol/L, BH4 status unknown (PMID:9860305; PMID:1312992). In summary this variant meets criteria to be classified as pathogenic for phenylketonuria in an autosomal recessive manner based on the ACMG/AMP criteria applied as specified by the PAH Expert Panel: (PM3_Strong, PP3, PS3, PP4_Moderate). LINK:https://erepo.genome.network/evrepo/ui/classification/CA229404/MONDO:0009861/006

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000088 ( 0 hom. )

Consequence

PAH
NM_000277.3 missense

Scores

Clinical Significance

Pathogenic reviewed by expert panel P:18O:1

Conservation

PhyloP100: 3.77

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]

PAH links:

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.

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
PAH	NM_000277.3 link	c.1223G>A	p.Arg408Gln	missense_variant	Exon 12 of 13	ENST00000553106.6	NP_000268.1	P00439A0A024RBG4
PAH	NM_001354304.2 link	c.1223G>A	p.Arg408Gln	missense_variant	Exon 13 of 14		NP_001341233.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6 link	c.1223G>A	p.Arg408Gln	missense_variant	Exon 12 of 13	1	NM_000277.3	ENSP00000448059.1		P00439

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

151990

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251438

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135886

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000272

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000876

AC:

128

AN:

1461530

Hom.:

Cov.:

AF XY:

0.0000715

AC XY:

AN XY:

727108

show subpopulations

Gnomad4 AFR exome

AF:

0.000120

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000103

Gnomad4 OTH exome

AF:

0.0000994

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152106

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74356

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000673

Hom.:

Bravo

AF:

0.0000340

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:18Other:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Phenylketonuria

Pathogenic:13

Jan 21, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 408 of the PAH protein (p.Arg408Gln). This variant is present in population databases (rs5030859, gnomAD 0.03%). This missense change has been observed in individual(s) with PAH-related disease (PMID: 1312992, 10471838, 24401910, 29317692). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 612). 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). This variant disrupts the p.Arg408 amino acid residue in PAH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 2014036, 12173030, 24401910). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Aug 01, 1992

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Sep 19, 2023

Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 15, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 26, 2021

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 26, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 05, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PAH c.1223G>A (p.Arg408Gln) results in a conservative amino acid change in the encoded protein sequence. Two of three in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.8e-05 in 251438 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in PAH causing Phenylalanine Hydroxylase Deficiency (Phenylketonuria) (4.8e-05 vs 0.0079), allowing no conclusion about variant significance. c.1223G>A has been reported in the literature in multiple individuals affected with Phenylalanine Hydroxylase Deficiency (Phenylketonuria) (Ho_2014, Aldamiz-Echevarria_2016, Jeannesson-Thivisol_2015). These data indicate that the variant is very likely to be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.1222C>T, p.Arg408Trp), supporting the critical relevance of codon 408 to PAH protein function. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in 30%-50% of normal activity (Aldamiz-Echevarria_2016). The following publications have been ascertained in the context of this evaluation (PMID: 24368688, 26666653, 27121329). ClinVar contains an entry for this variant (Variation ID: 612). Based on the evidence outlined above, the variant was classified as pathogenic. -

Dec 19, 2019

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000277.1(PAH):c.1223G>A(R408Q) is classified as pathogenic in the context of phenylalanine hydroxylase deficiency and can be associated with variant or non-PKU HPA. Sources cited for classification include the following: PMID 14722928, 1312992, 1355066, 1301200, and 8533759. Classification of NM_000277.1(PAH):c.1223G>A(R408Q) is based on the following criteria: This is a well-established pathogenic variant in the literature that has been observed more frequently in patients with clinical diagnoses than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -

Aug 05, 2018

ClinGen PAH Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

PAH-specific ACMG/AMP criteria applied: PM3_Strong: In trans with R408W, IVS4-1G>A, R241C (ClinGen, P) (PMID:1312992; PMID:14722928); PP3: ; PS3: Mutant enzyme activity of 46% in BioPKU (PMID:9860305); PP4_Moderate: ~830 uml/L w/o BH4 deficiency & 823 umol/L, BH4 status unknown (PMID:9860305; PMID:1312992). In summary this variant meets criteria to be classified as pathogenic for phenylketonuria in an autosomal recessive manner based on the ACMG/AMP criteria applied as specified by the PAH Expert Panel: (PM3_Strong, PP3, PS3, PP4_Moderate). -

Neonatal Disease Screening Center, Medical Genetics Center, Huaihua City Maternal and Child Health Care Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

PS3+PM3_VS+PM5+PP1+PP3+PP4_M -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PM3_VeryStrong+PS3+PM5 -

May 06, 2021

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with phenylketonuria (PKU; MIM#261600). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to glutamine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 14 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (252 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated catalytic domain (PMID: 30037505). (I) 0705 - The well-reported pathogenic variant, p.(Arg408Trp), affecting the same residue has previously been reported in association with phenylketonuria (ClinVar), however it is not considered a comparable variant as it has a major Grantham score, whereas this variant has a minor score, therefore cannot be used to inform pathogenicity. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. It has been reported in multiple individuals with mild PKU, mild hyperphenylalaninemia ( MHP) and non-PKU hyperphenylalaninemia (ClinVar, PMID: 1312992). (SP) 1002 - This variant has moderate functional evidence supporting abnormal protein function. Site-directed mutagenesis studies have shown a reduction of 41% in PAH activity compared to wild-type (PMID: 30037505). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not provided

Pathogenic:3Other:1

DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Jun 29, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 28, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Functional studies of the R408Q variant show significantly reduced enzyme activity compared to wildtype (PMID: 26803807); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 22975760, 21953985, 21228398, 10471838, 25750018, 24327145, 17935162, 12655546, 1312992, 23891399, 1355066, 1301200, 29102225, 29317692, 24401910, 14722928, 28676969, 29499199, 30037505, 29413232, 29316886, 30747360, 31355225, 30275481, 33677757, 32668217, 32778825, 35314707, 16253218, 33161754, 36703223, 36646061, 36755623, 36787440, 37443404, 36845377, 38105685, 26803807, 25596310) -

Feb 27, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP3, PP4_moderate, PM3_strong, PS3 -

PAH-related disorder

Pathogenic:1

Feb 16, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The PAH c.1223G>A variant is predicted to result in the amino acid substitution p.Arg408Gln. This variant has been reported in the homozygous state or with a second pathogenic PAH variant in many patients with phenylalanine hydroxylase deficiency (e.g., Zschocke et al. 1995. PubMed ID: 8533759; Eiken et al. 1996. PubMed ID: 8875186; Table S3, Hillert et al. 2020. PubMed ID: 32668217). The p.Arg408Gln amino acid substitution has been reported to reduce PAH enzyme activity to ~50% of wild-type (Zurflüh et al. 2008. PubMed ID: 17935162) and is generally considered a mild PAH variant (Liang et al. 2014. PubMed ID: 24401910). This variant has been classified as pathogenic by the ClinGen PAH Variant Curation Expert Panel as well as several other outside laboratories (https://www.ncbi.nlm.nih.gov/clinvar/variation/612/). Over twenty patients homozygous for the c.1223G>A (p.Arg408Gln) variant have been reported in the BioPKU database; the majority of these patients presented with mild hyperphenylalaninemia or mild PKU (http://www.biopku.org). In summary, we classify the c.1223G>A variant as pathogenic. -

Hyperphenylalaninemia

Pathogenic:1

Oct 04, 2024

Al Jalila Children’s Genomics Center, Al Jalila Childrens Speciality Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PM3_VeryStrong, PM2, PP4, PS3 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.70

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.50

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.98

D;D

Eigen

Uncertain

0.66

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Uncertain

0.85

LIST_S2

Pathogenic

1.0

D;D

M_CAP

Pathogenic

0.74

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

0.95

MutationAssessor

Pathogenic

3.8

H;.

PrimateAI

Benign

0.47

PROVEAN

Uncertain

-3.1

D;D

REVEL

Pathogenic

0.91

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.0020

D;D

Polyphen

1.0

D;.

Vest4

0.86

MutPred

0.95

Loss of methylation at R408 (P = 0.052);.;

MVP

0.98

MPC

0.25

ClinPred

0.95

GERP RS

4.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.80

gMVP

0.91

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over