rs199475680

Variant names:

• chr12-102877503-G-A
• rs199475680
• NM_000277.3:c.400C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP4 PM2 PVS1

This summary comes from the ClinGen Evidence Repository: This c.400C>T (p.Gln134Ter) variant in PAH was detected in a patient with PKU (PMID:17096675). This variant was absent in population databases. This was predicted as a null variant in PAH where LOF is a known mechanism of disease. This is a nonsense variant in exon 4 of 13 coding exons predicted to undergo nonsense mediated decay. In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PVS1,PM2,PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA229534/MONDO:0009861/006

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAH NM_000277.3 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:3 O:1
• Conservation: PhyloP100: 9.18
• Publications: 0 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

LOC124902999 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 11 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.
• 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.400C>T	p.Gln134*	stop_gained	Exon 4 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.400C>T	p.Gln134*	stop_gained	Exon 5 of 14		NP_001341233.1
PAH	XM_017019370.2	c.400C>T	p.Gln134*	stop_gained	Exon 4 of 7		XP_016874859.1
LOC124902999	XR_007063428.1	n.808-2376G>A		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.400C>T	p.Gln134*	stop_gained	Exon 4 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:3

Oct 14, 2022

ClinGen PAH Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This c.400C>T (p.Gln134Ter) variant in PAH was detected in a patient with PKU (PMID:17096675). This variant was absent in population databases. This was predicted as a null variant in PAH where LOF is a known mechanism of disease. This is a nonsense variant in exon 4 of 13 coding exons predicted to undergo nonsense mediated decay. In summary, this variant meets criteria to be classified as pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PVS1,PM2,PP4. -

Oct 15, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PAH c.400C>T (p.Gln134X) 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. The variant was absent in 251466 control chromosomes. c.400C>T has been reported in the literature in at least 1 individual affected with Phenylalanine Hydroxylase Deficiency (Phenylketonuria) (example, Hillert_2020). The following publication has been ascertained in the context of this evaluation (PMID: 32668217). ClinVar contains an entry for this variant (Variation ID: 102664). Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 21, 2015

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

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	0.58
CADD	Pathogenic	47
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		9.2
Vest4		0.98
GERP RS		5.9
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
Splicevardb		2.0
SpliceAI score (max)		0.28		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.28		Position offset: -41

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

Other links and lift over

dbSNP: rs199475680; hg19: chr12-103271281;