12-102844335-C-T

Position:

• chr12-102844335-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM3_Supporting PP4 PM2

This summary comes from the ClinGen Evidence Repository: The PAH variant c.1065+1G>A (IVS10+1G>A) affects the canonical splice site (donor site). Loss of function in the PAH gene is a known mechanism of disease. Exon skipping is predicted to not disrupt the reading frame. This variant is predicted to alter a region that is critical to protein function. The PAH variant c.1065+1G>A (IVS10+1G>A) was identified in two French patients with mild hyperphenylalaninemia (mHP, 180 < Phe < 600 μmol/L) with the likely pathogenic variant c.261C>A (p.Ser87Arg) and with the pathogenic variant c.1169A>G (p.Glu390Gly)(PMID:26666653). The PAH variant c.1065+1G>A was also reported in an European patient with PAH deficiency (PMID:10679941). According to gnomAD, the PAH variant c.1065+1G>A (IVS10+1G>A) is present at a low allele frequency in population databases, with the highest reported frequency in the European (Finnish) population (0.00005). In summary, this variant meets the criteria to be classified as likely pathogenic. PAH-specific ACMG/AMP criteria applied: PM2, PM3_Supporting, PP4, and PVS1_Strong. LINK:https://erepo.genome.network/evrepo/ui/classification/CA229315/MONDO:0009861/006

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: PAH NM_000277.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 O:1
• Conservation: PhyloP100: 7.91

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 8 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/exons	MANE	Protein	UniProt
PAH	NM_000277.3	c.1065+1G>A		splice_donor_variant		ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.1065+1G>A		splice_donor_variant			NP_001341233.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.1065+1G>A		splice_donor_variant		1	NM_000277.3	ENSP00000448059	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251134 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135716

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000414 AC: 6 AN: 1448756 Hom.: 0 Cov.: 30 AF XY: 0.00000416 AC XY: 3 AN XY: 721742

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000455

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 17, 2022	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 102501). This variant is also known as IVS10+1G>A. Disruption of this splice site has been observed in individual(s) with hyperphenylalaninemia (PMID: 29176022). This variant is present in population databases (rs62516147, gnomAD no frequency). This sequence change affects a donor splice site in intron 10 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). -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Aug 26, 2016	- -
Likely pathogenic, reviewed by expert panel	curation	ClinGen PAH Variant Curation Expert Panel	Mar 21, 2021	The PAH variant c.1065+1G>A (IVS10+1G>A) affects the canonical splice site (donor site). Loss of function in the PAH gene is a known mechanism of disease. Exon skipping is predicted to not disrupt the reading frame. This variant is predicted to alter a region that is critical to protein function. The PAH variant c.1065+1G>A (IVS10+1G>A) was identified in two French patients with mild hyperphenylalaninemia (mHP, 180 < Phe < 600 μmol/L) with the likely pathogenic variant c.261C>A (p.Ser87Arg) and with the pathogenic variant c.1169A>G (p.Glu390Gly)(PMID: 26666653). The PAH variant c.1065+1G>A was also reported in an European patient with PAH deficiency (PMID: 10679941). According to gnomAD, the PAH variant c.1065+1G>A (IVS10+1G>A) is present at a low allele frequency in population databases, with the highest reported frequency in the European (Finnish) population (0.00005). In summary, this variant meets the criteria to be classified as likely pathogenic. PAH-specific ACMG/AMP criteria applied: PM2, PM3_Supporting, PP4, and PVS1_Strong. -

not provided Other:1

not provided, no classification provided

literature only

DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.60		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.23		Position offset: -38
DS_DL_spliceai		0.60		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs62516147; hg19: chr12-103238113;