rs752792040

chr12-102894780-C-Achr12-102894780-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_000277.3(PAH):c.307G>T(p.Gly103Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000744 in 1,613,948 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. G103D) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:3
• Conservation: PhyloP100: 4.84

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.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 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 chr12-102894779-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1453858.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.745

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PAH	NM_000277.3	c.307G>T	p.Gly103Cys	missense_variant	3/13	ENST00000553106.6
LOC124902999	XR_007063428.1	n.863-9918C>A		intron_variant, non_coding_transcript_variant
PAH	NM_001354304.2	c.307G>T	p.Gly103Cys	missense_variant	4/14
PAH	XM_017019370.2	c.307G>T	p.Gly103Cys	missense_variant	3/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PAH	ENST00000553106.6	c.307G>T	p.Gly103Cys	missense_variant	3/13	1	NM_000277.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152098 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461850 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727222

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: 0.00000989

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152098 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74296

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:3

Revision: reviewed by expert panel

Submissions by phenotype

Phenylketonuria Pathogenic:1 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein	Jan 30, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 12, 2023	This sequence change replaces glycine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 103 of the PAH protein (p.Gly103Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hyperphenylalaninemia (PMID: 17502162, 24368688, 32668217; Invitae). ClinVar contains an entry for this variant (Variation ID: 553638). 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 with a negative predictive value of 80%. This variant disrupts the p.Gly103 amino acid residue in PAH. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 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. -
Uncertain significance, reviewed by expert panel	curation	ClinGen PAH Variant Curation Expert Panel	Jul 23, 2023	The c.307G>T (p.Gly103Cys) variant in PAH has been reported in 2 patients with PKU (BH4 deficiency not assessed/reported) (PP4; PMID: 17502162, 24368688). It was detected in unknown phase with a pathogenic variant c.1066-11G>A (PMID: 17502162) and a likely pathogenic variant p.Y154F (PMID: 24368688). This variant has extremely low frequency in ExAC (MAF=0.00001). Computational evidence supports a deleterious effect (REVEL=0.819). In summary, this variant meets criteria to be classified as uncertain significance for PAH. PAH-specific ACMG/AMP criteria applied: PP4, PM2_supporting, PM3_supporting, PP3_moderate. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Sep 01, 2017	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
Cadd	Uncertain	24
Dann	Uncertain	0.99
DEOGEN2	Benign	0.35	T;T;T;T
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.89	D;D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.74	D;D;D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Benign	0.98	L;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.44	N;N;N;N
REVEL	Pathogenic	0.82
Sift	Benign	0.077	T;T;T;T
Sift4G	Benign	0.14	T;T;T;.
Polyphen		0.98	D;.;.;.
Vest4		0.87
MutPred		0.39		Loss of disorder (P = 0.0488);.;Loss of disorder (P = 0.0488);Loss of disorder (P = 0.0488);
MVP		0.99
MPC		0.16
ClinPred		0.88	D
GERP RS		6.2
Varity_R		0.39
gMVP		0.75

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: rs752792040; hg19: chr12-103288558;