rs62514955

Variant names:

• chr12-102852813-A-T
• rs62514955
• NM_000277.3:c.842+2T>A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM3_Strong PP4_Moderate PM2 PVS1

This summary comes from the ClinGen Evidence Repository: The c.842+2T>A variant in PAH is a splice-site variant predicted to result in skipping of exon 8, leading to a frameshift, premature protein truncation, and NMD (PVS1). It is absent from ethnically diverse control databases, including gnomAD/ExAC, 1000 Genomes, and ESP (PM2). It is reported Pathogenic in Clinvar (ID 614). It has been reported among multiple patients with classic PKU, with BH4 deficiency formally excluded (PMID:17557229; PMID:21307867) (PP4_Moderate) and has been reported in trans with multiple Pathogenic and Likely Pathogenic mutations, including R111X (P, ClinGen); P281L (P, ClinGen); R413P (P, ClinGen); R243Q (P, ClinGen); R261Q (LP/P, ClinGen); R400T (unknown, ClinGen) (PMID:17557229) (PM3_Strong).Classification: PathogenicSupporting Criteria: PVS1, PM2, PM3_Strong, PP4_Moderate LINK:https://erepo.genome.network/evrepo/ui/classification/CA229813/MONDO:0009861/006

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PAH NM_000277.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:5 O:1
• Conservation: PhyloP100: 9.32
• Publications: 10 publications found

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 Gene-Disease associations (from GenCC):

• phenylketonuria

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Myriad Women’s Health
• classic phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• maternal phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mild hyperphenylalaninemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mild phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• tetrahydrobiopterin-responsive hyperphenylalaninemia/phenylketonuria

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PVS1: 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.
• 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.842+2T>A		splice_donor_variant, intron_variant	Intron 7 of 12	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.842+2T>A		splice_donor_variant, intron_variant	Intron 8 of 13		NP_001341233.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.842+2T>A		splice_donor_variant, intron_variant	Intron 7 of 12	1	NM_000277.3	ENSP00000448059.1
PAH	ENST00000307000.7	c.827+2T>A		splice_donor_variant, intron_variant	Intron 8 of 13	5		ENSP00000303500.2
PAH	ENST00000635477.1	c.2+2T>A		splice_donor_variant, intron_variant	Intron 1 of 5	5		ENSP00000489230.1
PAH	ENST00000549247.6	n.601+2T>A		splice_donor_variant, intron_variant	Intron 1 of 5	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461720 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727172

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111888

Other (OTH) AF: 0.00 AC: 0 AN: 60380

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:5

Mar 09, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 01, 1989

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jan 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 7 of the PAH gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PAH are known to be pathogenic (PMID: 1301187, 9634518). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with phenylketonuria (PMID: 26322415, 27264808). This variant is also known as IVS7+2T>A. ClinVar contains an entry for this variant (Variation ID: 614). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Apr 16, 2020

ClinGen PAH Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.842+2T>A variant in PAH is a splice-site variant predicted to result in skipping of exon 8, leading to a frameshift, premature protein truncation, and NMD (PVS1). It is absent from ethnically diverse control databases, including gnomAD/ExAC, 1000 Genomes, and ESP (PM2). It is reported Pathogenic in Clinvar (ID 614). It has been reported among multiple patients with classic PKU, with BH4 deficiency formally excluded (PMID: 17557229; PMID: 21307867) (PP4_Moderate) and has been reported in trans with multiple Pathogenic and Likely Pathogenic mutations, including R111X (P, ClinGen); P281L (P, ClinGen); R413P (P, ClinGen); R243Q (P, ClinGen); R261Q (LP/P, ClinGen); R400T (unknown, ClinGen) (PMID: 17557229) (PM3_Strong). Classification: Pathogenic Supporting Criteria: PVS1, PM2, PM3_Strong, PP4_Moderate -

-

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PVS1+PM3_VeryStrong+PP4 -

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
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.3
GERP RS		5.7
PromoterAI		-0.30	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.94		Position offset: 2

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

Other links and lift over

dbSNP: rs62514955; hg19: chr12-103246591;