rs5030859

chr12-102840492-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000277.3(PAH):c.1223G>A(p.Arg408Gln) variant causes a missense change. The variant allele was found at a frequency of 0.000083 in 1,613,636 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R408W) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000088 (0 hom.)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:15 O:1
• Conservation: PhyloP100: 3.77

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000277.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-102840493-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 577.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986
• PP5: Variant 12-102840492-C-T is Pathogenic according to our data. Variant chr12-102840492-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 612.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr12-102840492-C-T is described in Lovd as [Pathogenic]. Variant chr12-102840492-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PAH	NM_000277.3	c.1223G>A	p.Arg408Gln	missense_variant	12/13	ENST00000553106.6
PAH	NM_001354304.2	c.1223G>A	p.Arg408Gln	missense_variant	13/14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PAH	ENST00000553106.6	c.1223G>A	p.Arg408Gln	missense_variant	12/13	1	NM_000277.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000395 AC: 6 AN: 151990 Hom.: 0 Cov.: 32

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: 12 AN: 251438 Hom.: 0 AF XY: 0.0000368 AC XY: 5 AN XY: 135886

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.: 0 Cov.: 31 AF XY: 0.0000715 AC XY: 52 AN XY: 727108

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: 6 AN: 152106 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74356

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.: 0

Bravo AF: 0.0000340

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ExAC AF: 0.0000494 AC: 6

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:12

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Dec 19, 2019	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. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Neonatal Disease Screening Center, Medical Genetics Center, Huaihua City Maternal and Child Health Care Hospital	-	PS3+PM3_VS+PM5+PP1+PP3+PP4_M -
Pathogenic, no assertion criteria provided	literature only	OMIM	Aug 01, 1992	- -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Dec 15, 2021	- -
Pathogenic, reviewed by expert panel	curation	ClinGen PAH Variant Curation Expert Panel	Aug 05, 2018	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). -
Pathogenic, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	May 06, 2021	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 -
Pathogenic, criteria provided, single submitter	clinical testing	Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences	Sep 19, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 08, 2018	Variant summary: The PAH c.1223G>A (p.Arg408Gln) variant located in the Aromatic amino acid hydroxylas, C-terminal domain (InterPro) involves the alteration of a conserved nucleotide and 4/5 in silico tools predict a damaging outcome for this variant. This variant was found in 13/277144 control chromosomes (gnomAD) at a frequency of 0.0000469, which does not exceed the estimated maximal expected allele frequency of a pathogenic PAH variant (0.0079057). Multiple publications have cited the variant in affected compound heterozygous individuals, presenting with a significant decrease in PAH activity. In support of this, there are other variants at the 408 codon that have been reported in patients with PKU (R408L, R408W), suggesting the codon is important for function. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 20, 2024	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). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jul 26, 2021	- -

not provided Pathogenic:2 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 29, 2017	- -
not provided, no classification provided	literature only	DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Al Jalila Children's Genomics Center, Al Jalila Childrens Speciality Hospital	Dec 17, 2022	- -

PAH-related condition Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 16, 2024

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.50
Cadd	Pathogenic	28
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	D;D
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Pathogenic	0.74	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	3.8	H;.
MutationTaster	Benign	1.0	A;A
PrimateAI	Benign	0.47	T
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	D
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

Other links and lift over

dbSNP: rs5030859; hg19: chr12-103234270;