rs62514959

Positions:

• chr12-102844424-C-G
• chr12-102844424-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM5_Supporting PP4 PM2_Supporting PM3_Supporting PP3_Moderate

This summary comes from the ClinGen Evidence Repository: The NM_000277.3(PAH):c.977G>C (p.Trp326Ser) variant is a missense variant in exon 10/13 of PAH. This variant has been previously reported in at least one proband with hyperphenylalanemia (HPA; Palmieri, A. (2013). MOLECULAR ANALYSIS OF PHENYLALANINE HYDROXYLASE GENE IN SOUTH ITALY PATIENTS AFFECTED BY PHENYLKETONURIA) in whom BH4 deficiency was not formally excluded by normal urine pterins and normal DHPR activity, or sequencing of genes in the BH4 cofactor metabolism pathway to exclude a defect of BH4 cofactor metabolism (PP4_Supporting). This variant has been reported in at least one proband with the genotype p.Leu48Ser/p.Trp326Ser (phase not confirmed) phenotype (PMID:32668217); the p.Leu48Ser variant is path in ClinVar by PAH VCEP (Var ID: 608) (PM3_Supporting). The variant is absent from ethnically diverse control databases, including gnomAD/ExAC, 1000 Genomes, and ESP (PM2). The variant is predicted damaging by multiple in-silico missense predictors, including REVEL (REVEL score 0.874) (PP3_Moderate). A different missense variant at the same site, p.Trp326Cys, has been previously reported in one patient with HPA (PMID:36537053), BH4 deficiency not excluded, in presumed trans w/p.R408W (path by PAH VCEP, ClinVar ID 577); the p.W326C variant qualifies as likely path (PM3_Supp, PP3_Mod, PP4_Mod (hyperphenylalanemia, BH4 deficiency excluded by sequencing of genes in sequencing of genes in the BH4 cofactor metabolism pathway, PM2_Supp), such that PM5_Supporting is met. In summary, this variant meets criteria to be classified as Likely Pathogenic based on the ACMG/AMP criteria applied, as specified by the ClinGen Phenylketonuria Variant Curation Expert Panel (Specifications Version 2.0): PM2_Supporting, PM3_Supporting, PM5_Supporting, PP4_Supporting, PP3_Moderate. LINK:https://erepo.genome.network/evrepo/ui/classification/CA16020913/MONDO:0009861/006

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Uncertain significance reviewed by expert panel U:1
• Conservation: PhyloP100: 6.06

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 Likely_pathogenic. Variant got 6 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PAH	NM_000277.3	c.977G>C	p.Trp326Ser	missense_variant	10/13	ENST00000553106.6
PAH	NM_001354304.2	c.977G>C	p.Trp326Ser	missense_variant	11/14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PAH	ENST00000553106.6	c.977G>C	p.Trp326Ser	missense_variant	10/13	1	NM_000277.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Uncertain:1

Uncertain significance, reviewed by expert panel

curation

ClinGen PAH Variant Curation Expert Panel

Dec 25, 2020

The NM_000277.3(PAH):c.977G>C (p.Trp326Ser) variant is a missense variant in exon 10/13 of PAH. The variant is listed in BioPKU (ID PAH0407) but does not appear to have been reported in the published literature. The variant is absent from ethnically diverse control databases, including gnomAD/ExAC, 1000 Genomes, and ESP (PM2). The variant is predicted damaging by multiple in-silico missense predictors, including REVEL (REVEL score 0.874) (PP3). Classification: VUS Supporting Criteria: PM2; PP3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.87	D;D
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	4.8	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-13	D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	D;.
Vest4		0.97
MutPred		0.88		Loss of stability (P = 0.1278);.;
MVP		1.0
MPC		0.28
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-103238202;