NM_000277.3:c.439C>T

Variant names:

• chr12-102877464-G-A
• rs199475624
• NM_000277.3:c.439C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PP3 PM3_Strong PP4_Moderate PM2

This summary comes from the ClinGen Evidence Repository: This c.439C>T (p.Pro147Ser) variant in PAH was reported in at least 5 patients with PAH deficiency, detected with pathogenic variants p.Arg243Gln (PMID:27121329), p.S349P (PMID:15589814), c.1045T>C, c.782G>A (PMID:24941924) and p.A403V (PMID:10234516). DHPR activity, biopterin and/or pteridine analysis was performed to rule out other causes of hyperphenylalaninemia (PMID:27121329). This variant is present at an extremely low frequency in gnomAD (MAF=0.00003). Computational evidence for this missense variant supports a deleterious effect. In summary, this variant meets criteria to be classified as likely pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM3_strong, PM2, PP4_moderate, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA229541/MONDO:0009861/006

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: PAH NM_000277.3 missense, splice_region
• Scores: Splicing: ADA: 0.9990
• Clinical Significance: Likely pathogenic reviewed by expert panel P:7 O:1
• Conservation: PhyloP100: 9.18
• Publications: 5 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: Likely_pathogenic. The variant received 9 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.439C>T	p.Pro147Ser	missense_variant, splice_region_variant	Exon 4 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.439C>T	p.Pro147Ser	missense_variant, splice_region_variant	Exon 5 of 14		NP_001341233.1
PAH	XM_017019370.2	c.439C>T	p.Pro147Ser	missense_variant, splice_region_variant	Exon 4 of 7		XP_016874859.1
LOC124902999	XR_007063428.1	n.808-2415G>A		intron_variant	Intron 1 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.439C>T	p.Pro147Ser	missense_variant, splice_region_variant	Exon 4 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251484 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459846 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726348

African (AFR) AF: 0.00 AC: 0 AN: 33438

American (AMR) AF: 0.0000224 AC: 1 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86228

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1110132

Other (OTH) AF: 0.00 AC: 0 AN: 60330

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:7 Other:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:6

Feb 23, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). The variant is located in a mutational hot spot and/or well-established functional domain in which established pathogenic variants have been reported. Missense changes are a common disease-causing mechanism. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.96; 3Cnet: 1.00). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000102669). The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least 2 similarly affected unrelated individuals (PMID: 10234516, 15589814, 24941924, 27121329). A different missense change at the same codon (p.Pro147Leu) has been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000102670). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Oct 15, 2020

ClinGen PAH Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

This c.439C>T (p.Pro147Ser) variant in PAH was reported in at least 5 patients with PAH deficiency, detected with pathogenic variants p.Arg243Gln (PMID: 27121329), p.S349P (PMID: 15589814), c.1045T>C, c.782G>A (PMID: 24941924) and p.A403V (PMID: 10234516). DHPR activity, biopterin and/or pteridine analysis was performed to rule out other causes of hyperphenylalaninemia (PMID: 27121329). This variant is present at an extremely low frequency in gnomAD (MAF=0.00003). Computational evidence for this missense variant supports a deleterious effect. In summary, this variant meets criteria to be classified as likely pathogenic for PAH. PAH-specific ACMG/AMP criteria applied: PM3_strong, PM2, PP4_moderate, PP3. -

Oct 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 147 of the PAH protein (p.Pro147Ser). This variant is present in population databases (rs199475624, gnomAD 0.003%). This missense change has been observed in individual(s) with PAH-related conditions (PMID: 10598814, 27121329). ClinVar contains an entry for this variant (Variation ID: 102669). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This variant disrupts the p.Pro147 amino acid residue in PAH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26322415, 27121329, 31355225). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Jun 01, 2018

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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. -

Mar 18, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 16, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1 Other:1

-

DeBelle Laboratory for Biochemical Genetics, MUHC/MCH RESEARCH INSTITUTE

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Dec 30, 2020

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant has been reported in several symptomatic phenylketonuria patients in literature (PMIDs: 8981952 (1997), 10234516 (1999), 15589814 (2004), 24941924 (2015), and 27121329 (2016)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is disease causing and damaging. Based on the available information, the variant is predicted to be likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	1.0	D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.9	H;.
PhyloP100		9.2
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-7.4	D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0080	D;D
Polyphen		1.0	D;.
Vest4		0.99
MutPred		0.94		Gain of glycosylation at P147 (P = 0.0354);.;
MVP		0.98
MPC		0.24
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Varity_R		0.86
gMVP		0.92
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.80
Splicevardb		2.0
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

Other links and lift over

dbSNP: rs199475624; hg19: chr12-103271242;