rs62508587

chr12-102855260-CAG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000277.3(PAH):c.580_581del(p.Leu194GlufsTer5) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,766 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PAH NM_000277.3 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:3 O:1
• Conservation: PhyloP100: 9.32

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.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-102855260-CAG-C is Pathogenic according to our data. Variant chr12-102855260-CAG-C is described in ClinVar as [Pathogenic]. Clinvar id is 102741.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr12-102855260-CAG-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PAH	NM_000277.3	c.580_581del	p.Leu194GlufsTer5	frameshift_variant	6/13	ENST00000553106.6
PAH	NM_001354304.2	c.580_581del	p.Leu194GlufsTer5	frameshift_variant	7/14
PAH	XM_017019370.2	c.580_581del	p.Leu194GlufsTer5	frameshift_variant	6/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PAH	ENST00000553106.6	c.580_581del	p.Leu194GlufsTer5	frameshift_variant	6/13	1	NM_000277.3	P1
PAH	ENST00000549111.5	n.676_677del		non_coding_transcript_exon_variant	6/6	1
PAH	ENST00000307000.7	c.565_566del	p.Leu189GlufsTer5	frameshift_variant	7/14	5
PAH	ENST00000551988.5			downstream_gene_variant		3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461766 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 727184

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:3

Pathogenic, reviewed by expert panel	curation	ClinGen PAH Variant Curation Expert Panel	Oct 30, 2020	The c.578_579del PAH variant has been identified in at least one patient with classic PKU (PMID: 26666653). The patient was compound heterozygous with the pathogenic variant Leu348Val (ClinVar 92727). This variant is absent from 1000G, ESP, and gnomAD databases. This variant leads to the frameshift Leu194GlufsTer5, creating a stop codon in exon 6 of 13 which is predicted to cause NMD. In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PVS1, PP4, PM2, PM3_supporting. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Jun 16, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 22, 2022	Variant summary: PAH c.580_581delCT (p.Leu194GlufsX5) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251338 control chromosomes (gnomAD). c.580_581delCT has been reported in the literature in multiple individuals affected with Phenylalanine Hydroxylase Deficiency (Phenylketonuria, e.g. Aulehla-Scholz_2003, Sarkissian_2012, Jeannesson-Thivisol_2015). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submitter (an expert panel) has assessed this variant since 2014: the variant was classified as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

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

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: rs62508587; hg19: chr12-103249038;