chr12-102851689-G-T

Variant names:

• chr12-102851689-G-T
• rs1555204295
• NM_000277.3:c.910C>A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP2 PP3 PP5_Very_Strong

The NM_000277.3(PAH):​c.910C>A​(p.Gln304Lys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q304R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PAH NM_000277.3 missense, splice_region
• Scores: Splicing: ADA: 0.9650
• Clinical Significance: Likely pathogenic reviewed by expert panel P:1
• Conservation: PhyloP100: 9.60
• Publications: 2 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

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PM1: In a hotspot region, there are 29 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000277.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-102851688-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 102891.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 440 curated pathogenic missense variants (we use a threshold of 10). The gene has 8 curated benign missense variants. Gene score misZ: -0.64755 (below the threshold of 3.09). Trascript score misZ: -0.0084567 (below the threshold of 3.09). GenCC associations: The gene is linked to phenylketonuria, tetrahydrobiopterin-responsive hyperphenylalaninemia/phenylketonuria, maternal phenylketonuria, classic phenylketonuria, mild phenylketonuria, mild hyperphenylalaninemia.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 12-102851689-G-T is Pathogenic according to our data. Variant chr12-102851689-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1185009.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PAH	NM_000277.3	c.910C>A	p.Gln304Lys	missense_variant, splice_region_variant	Exon 8 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.910C>A	p.Gln304Lys	missense_variant, splice_region_variant	Exon 9 of 14		NP_001341233.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.910C>A	p.Gln304Lys	missense_variant, splice_region_variant	Exon 8 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:1

Dec 09, 2019

ClinGen PAH Variant Curation Expert Panel

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.910C>A (p.Gln304Lys) variant in PAH has been reported in at least one individual with PKU (BH4 deficiency ruled out) (PMID: 29499199, 26503515, 30050108) in trans with pathogenic variant p.R261*. The p.Gln304Lys variant is absent from gnomAD and the ESP population databases. A deleterious effect is predicted in SIFT, Polyphen-2, MutationTaster, and REVEL=0.973. Another missense change at the same codon has been reported (p.Gln304Arg), however with unknown pathogenicity. Overall, the c.910C>A variant is classified as likely pathogenic. PAH-specific ACMG/AMP criteria applied: PP3, PM2, PM3, PP4_moderate. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.60	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.5	M;.
PhyloP100		9.6
PrimateAI	Uncertain	0.79	T
PROVEAN	Uncertain	-3.9	D;D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;.
Vest4		0.89
MutPred		0.86		Gain of ubiquitination at Q304 (P = 0.0289);.;
MVP		0.99
MPC		0.26
ClinPred		0.99	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.99
Mutation Taster		=5/95	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.97
dbscSNV1_RF	Pathogenic	0.80
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: rs1555204295; hg19: chr12-103245467;