rs778154939

chr12-102852857-T-Achr12-102852857-T-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Strong

The NM_000277.3(PAH):c.800A>T(p.Gln267Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,850 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q267E) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:1
• Conservation: PhyloP100: 8.02

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 14 ACMG points.

• PM1: In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 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 chr12-102852858-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 102839.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 12-102852857-T-A is Pathogenic according to our data. Variant chr12-102852857-T-A is described in ClinVar as [Uncertain_significance]. Clinvar id is 225135.Status of the report is reviewed_by_expert_panel, 3 stars. We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PAH	NM_000277.3	c.800A>T	p.Gln267Leu	missense_variant	7/13	ENST00000553106.6
PAH	NM_001354304.2	c.800A>T	p.Gln267Leu	missense_variant	8/14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PAH	ENST00000553106.6	c.800A>T	p.Gln267Leu	missense_variant	7/13	1	NM_000277.3	P1
PAH	ENST00000307000.7	c.785A>T	p.Gln262Leu	missense_variant	8/14	5
PAH	ENST00000549247.6	n.559A>T		non_coding_transcript_exon_variant	1/6	2
PAH	ENST00000635477.1			upstream_gene_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251368 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135838

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS 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: 6.84e-7 AC: 1 AN: 1461850 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727228

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:2 Uncertain:1

Uncertain significance, reviewed by expert panel	curation	ClinGen PAH Variant Curation Expert Panel	Aug 10, 2018	PAH-specific ACMG/AMP criteria applied: PM2: Absent from 1000G, ESP. Extremely low frequency in ExAC and gnomAD ( 0.00001, 0.000004063); PP3: Predicted deleterious in SIFT, Polyphen2, MutationTaster. REVEL=0.975; PP4_Moderate: Q267L found in 1 Japanese PKU allele and in 1 Chinese PKU patient. Analysis of dihydropteridine reductase activity in red blood cells, biopterin loading test and/or pteridine analysis in urine was performed in the Japanese study. Upgraded per ClinGen Metabolic workgroup. (PMID:21307867; PMID:24078561; PMID:26503515). In summary this variant meets criteria to be classified as uncertain significance for phenylketonuria in an autosomal recessive manner based on the ACMG/AMP criteria applied as specified by the PAH Expert Panel: (PM2, PP3, PP4_Moderate). -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 08, 2021	For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Gln267 amino acid residue in PAH. Other variant(s) that disrupt this residue have been observed in individuals with PAH-related conditions (PMID: 32668217), which suggests that this may be a clinically significant amino acid residue. 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 expected to disrupt PAH protein function. ClinVar contains an entry for this variant (Variation ID: 225135). This missense change has been observed in individual(s) with hyperphenylalaninemia (PMID: 21307867, 24078561, 26503515, 31355225, 32668217). This variant is present in population databases (rs778154939, ExAC 0.01%). This sequence change replaces glutamine with leucine at codon 267 of the PAH protein (p.Gln267Leu). The glutamine residue is highly conserved and there is a moderate physicochemical difference between glutamine and leucine. -
Likely pathogenic, no assertion criteria provided	clinical testing	Department of Prenatal Diagnosis, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital	Oct 01, 2013	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	29
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D;D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.9	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-6.7	D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		1.0	D;.
Vest4		0.95
MutPred		0.88		Gain of sheet (P = 0.0827);.;
MVP		0.98
MPC		0.24
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.95
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs778154939; hg19: chr12-103246635;