rs796064502

Variant names:

• chr12-102894845-G-T
• rs796064502
• NM_000277.3:c.242C>A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP4_Moderate PP3 PM3

This summary comes from the ClinGen Evidence Repository: The c.242C>A (p.Thr81Asn) variant in PAH is reported in 1 PKU patient. PAH and BH4DH genes were sequenced. It was detected with p.V230I which is interpreted as Pathogenic/Likely Pathogenic in ClinVar. (PMID:23942198) This variant is absent from ExAC, gnomAD, 1000G, and ESP. A deleterious effect is predicted in SIFT, MutationTaster, and Polyphen-2. In summary, this variant meets criteria to be classified as likely pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM2, PP4_Moderate, PM3, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA275937/MONDO:0009861/006

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3
• Conservation: PhyloP100: 5.35

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]

LOC124902999 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 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.
• 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.242C>A	p.Thr81Asn	missense_variant	Exon 3 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.242C>A	p.Thr81Asn	missense_variant	Exon 4 of 14		NP_001341233.1
PAH	XM_017019370.2	c.242C>A	p.Thr81Asn	missense_variant	Exon 3 of 7		XP_016874859.1
LOC124902999	XR_007063428.1	n.863-9853G>T		intron_variant	Intron 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.242C>A	p.Thr81Asn	missense_variant	Exon 3 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461526 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727098

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: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:3

Oct 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 208180). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 81 of the PAH protein (p.Thr81Asn). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of hyperphenylalaninemia (PMID: 23942198; Invitae). 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 not expected to disrupt PAH protein function. This variant disrupts the p.Thr81 amino acid residue in PAH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 8659548, 23430918). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Dec 10, 2018

ClinGen PAH Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.242C>A (p.Thr81Asn) variant in PAH is reported in 1 PKU patient. PAH and BH4DH genes were sequenced. It was detected with p.V230I which is interpreted as Pathogenic/Likely Pathogenic in ClinVar. (PMID: 23942198) This variant is absent from ExAC, gnomAD, 1000G, and ESP. A deleterious effect is predicted in SIFT, MutationTaster, and Polyphen-2. In summary, this variant meets criteria to be classified as likely pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM2, PP4_Moderate, PM3, PP3. -

-

Inserm U 954, Faculté de Médecine de Nancy

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: not provided

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	D;D;D;D
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.86	D;D;D;D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.82	D;D;D;D
MetaSVM	Uncertain	0.79	D
MutationAssessor	Benign	1.9	L;.;.;.
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-2.2	N;N;N;D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Uncertain	0.026	D;D;D;.
Polyphen		0.50	P;.;.;.
Vest4		0.83
MutPred		0.56		Gain of catalytic residue at T81 (P = 0.0135);.;Gain of catalytic residue at T81 (P = 0.0135);Gain of catalytic residue at T81 (P = 0.0135);
MVP		0.99
MPC		0.092
ClinPred		0.96	D
GERP RS		5.3
Varity_R		0.91
gMVP		0.94

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: rs796064502; hg19: chr12-103288623;