rs62508693

Variant names:

• chr12-102851751-A-T
• rs62508693
• NM_000277.3:c.848T>A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PP4_Moderate PM2 PP3 PM5 PM3_Strong

This summary comes from the ClinGen Evidence Repository: The c.848T>A (p.Ile283Asn) variant in PAH is absent from population databases and predicted damaging with in silico predictors. It is a novel missense change in a residue where a different pathogenic variant has been identified (c.847A>T (p.Ile283Phe). It has been identified in multiple affected individuals in trans with known pathogenic variants (PMID:9521426, 26413448), and was identified in a patient in which a defect in BH4 metabolism had been excluded. In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM3_strong, PM2, PM5, PP4_Moderate, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA229821/MONDO:0009861/006

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:3 O:1
• Conservation: PhyloP100: 4.01

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 11 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: 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	c.848T>A	p.Ile283Asn	missense_variant	Exon 8 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.848T>A	p.Ile283Asn	missense_variant	Exon 9 of 14		NP_001341233.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.848T>A	p.Ile283Asn	missense_variant	Exon 8 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74394

Gnomad4 AFR AF: 0.00

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

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:3

Apr 13, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 10, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant disrupts the p.Ile283 amino acid residue in PAH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8097423, 11161839, 24350308, 25596310). 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. 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. ClinVar contains an entry for this variant (Variation ID: 102877). This missense change has been observed in individual(s) with hyperphenylalaninemia (PMID: 9521426, 32668217). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with asparagine at codon 283 of the PAH protein (p.Ile283Asn). The isoleucine residue is highly conserved and there is a large physicochemical difference between isoleucine and asparagine. -

Dec 09, 2018

ClinGen PAH Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.848T>A (p.Ile283Asn) variant in PAH is absent from population databases and predicted damaging with in silico predictors. It is a novel missense change in a residue where a different pathogenic variant has been identified (c.847A>T (p.Ile283Phe). It has been identified in multiple affected individuals in trans with known pathogenic variants (PMID: 9521426, 26413448), and was identified in a patient in which a defect in BH4 metabolism had been excluded. In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM3_strong, PM2, PM5, PP4_Moderate, PP3. -

not provided Other:1

-

DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.6	H;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-5.4	D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0060	D;D
Polyphen		1.0	D;.
Vest4		0.98
MutPred		0.90		Gain of disorder (P = 0.0107);.;
MVP		1.0
MPC		0.28
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.96
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

Other links and lift over

dbSNP: rs62508693; hg19: chr12-103245529;