12-102894900-T-C

Variant names:

• chr12-102894900-T-C
• rs199475568
• NM_000277.3:c.187A>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000277.3(PAH):​c.187A>G​(p.Thr63Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,118 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T63P) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.13
• 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: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 24 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
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PAH	NM_000277.3	c.187A>G	p.Thr63Ala	missense_variant	Exon 3 of 13	ENST00000553106.6	NP_000268.1
PAH	NM_001354304.2	c.187A>G	p.Thr63Ala	missense_variant	Exon 4 of 14		NP_001341233.1
PAH	XM_017019370.2	c.187A>G	p.Thr63Ala	missense_variant	Exon 3 of 7		XP_016874859.1
LOC124902999	XR_007063428.1	n.863-9798T>C		intron_variant	Intron 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PAH	ENST00000553106.6	c.187A>G	p.Thr63Ala	missense_variant	Exon 3 of 13	1	NM_000277.3	ENSP00000448059.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152118 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: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152118 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74322

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41404

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68014

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.88	D;D;D;D
Eigen	Uncertain	0.26
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D;D;D;D
M_CAP	Benign	0.071	D
MetaRNN	Uncertain	0.66	D;D;D;D
MetaSVM	Pathogenic	1.2	D
MutationAssessor	Pathogenic	3.1	M;.;.;.
PhyloP100		7.1
PrimateAI	Uncertain	0.71	T
PROVEAN	Benign	-2.0	N;N;N;N
REVEL	Uncertain	0.59
Sift	Benign	0.63	T;T;T;D
Sift4G	Benign	0.78	T;T;T;.
Polyphen		0.28	B;.;.;.
Vest4		0.82
MutPred		0.36		Loss of phosphorylation at T63 (P = 0.1459);.;Loss of phosphorylation at T63 (P = 0.1459);Loss of phosphorylation at T63 (P = 0.1459);
MVP		0.92
MPC		0.031
ClinPred		0.98	D
GERP RS		6.2
Varity_R		0.60
gMVP		0.77
Mutation Taster		=16/84	disease causing

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

Other links and lift over

dbSNP: rs199475568; hg19: chr12-103288678;