12-102855222-T-C

Variant names:

• chr12-102855222-T-C
• rs62508721
• NM_000277.3:c.620A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PP3 PP4 PM2_Supporting PM3_Strong

This summary comes from the ClinGen Evidence Repository: The NM_000277.3:c.620A>G variant in PAH is a missense variant predicted to cause substitution of asparagine by serine at amino acid 207 (p.Asn207Ser). This variant has been detected in at least 5 unrelated individuals with PAH deficiency (PMID:32668217, PMID:9048935). Of these individuals, one was a compound heterozygote for the variant and a likely pathogenic variant, p.Pro281Leu, in trans (phase confirmed by parental testing) (PMID:9048935), and four were compound heterozygotes for the variant and pathogenic variants, p.Ala300Ser, p.Ala403Val, p.Glu390Gly, p.Arg252Gln, in unknown phase (PMID:32668217) (3pts total, PM3_Strong). One of these individuals had plasma phenylalanine >120 μmol/L without the exclusion of a defect of BH4 cofactor metabolism (PMID:9048935) (PP4). This variant is absent in gnomAD v2.1.1 (PM2_Supporting). The computational predictor REVEL gives a score of 0.77 which is above the threshold of 0.75, evidence that correlates with impact to PAH function (PP3). There is a ClinVar entry for this variant (Variation ID: 102765, 1 star review status) with one submitter classifying the variant as pathogenic, one submitter classifying the variant as likely pathogenic, and one submitter classifying the variant as a variant of uncertain significance. In summary, this variant meets the criteria to be classified as likely pathogenic for PAH deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen PAH Variant Curation Expert Panel (Specifications Version 2.0): PM2_Supporting, PM3_Strong, PP3, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA229665/MONDO:0009861/006

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PAH NM_000277.3 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 U:1 O:1
• Conservation: PhyloP100: 3.27
• Publications: 6 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: Likely_pathogenic. The variant received 7 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.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000277.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PAH	NM_000277.3	MANE Select	c.620A>G	p.Asn207Ser	missense	Exon 6 of 13	NP_000268.1
	PAH	NM_001354304.2		c.620A>G	p.Asn207Ser	missense	Exon 7 of 14	NP_001341233.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PAH	ENST00000553106.6	TSL:1 MANE Select	c.620A>G	p.Asn207Ser	missense	Exon 6 of 13	ENSP00000448059.1
	PAH	ENST00000549111.5	TSL:1	n.716A>G		non_coding_transcript_exon	Exon 6 of 6
	PAH	ENST00000906695.1		c.620A>G	p.Asn207Ser	missense	Exon 6 of 14	ENSP00000576754.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461804 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727204

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111938

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
3	1	-	Phenylketonuria (4)
-	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		3.3
PrimateAI	Uncertain	0.55	T
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.77
Sift	Benign	0.18	T
Sift4G	Benign	0.59	T
Polyphen		0.92	P
Vest4		0.90
MutPred		0.85		Gain of catalytic residue at N207 (P = 0.0682)
MVP		0.98
MPC		0.21
ClinPred		0.99	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.72
gMVP		0.91
Mutation Taster		=4/96	disease causing (ClinVar)

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: rs62508721; hg19: chr12-103249000; COSMIC: COSV61013938; COSMIC: COSV61013938;