rs118203921
Variant summary
Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong
The NM_000277.3(PAH):c.776C>T(p.Ala259Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,982 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A259T) has been classified as Pathogenic.
Frequency
Consequence
NM_000277.3 missense
Scores
Clinical Significance
Conservation
Publications
- phenylketonuriaInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Myriad Women’s Health
- classic phenylketonuriaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- maternal phenylketonuriaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- mild hyperphenylalaninemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- mild phenylketonuriaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- tetrahydrobiopterin-responsive hyperphenylalaninemia/phenylketonuriaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 19 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| PAH | NM_000277.3 | c.776C>T | p.Ala259Val | missense_variant | Exon 7 of 13 | ENST00000553106.6 | NP_000268.1 | |
| PAH | NM_001354304.2 | c.776C>T | p.Ala259Val | missense_variant | Exon 8 of 14 | NP_001341233.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| PAH | ENST00000553106.6 | c.776C>T | p.Ala259Val | missense_variant | Exon 7 of 13 | 1 | NM_000277.3 | ENSP00000448059.1 | ||
| PAH | ENST00000307000.7 | c.761C>T | p.Ala254Val | missense_variant | Exon 8 of 14 | 5 | ENSP00000303500.2 | |||
| PAH | ENST00000549247.6 | n.535C>T | non_coding_transcript_exon_variant | Exon 1 of 6 | 2 | |||||
| PAH | ENST00000635477.1 | c.-65C>T | upstream_gene_variant | 5 | ENSP00000489230.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152142Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251340 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461840Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727226 show subpopulations
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152142Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74328 show subpopulations
ClinVar
Submissions by phenotype
Phenylketonuria Pathogenic:5
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This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 259 of the PAH protein (p.Ala259Val). This variant is present in population databases (rs118203921, gnomAD 0.007%). This missense change has been observed in individual(s) with phenylketonuria (PMID: 2035532, 18299955, 26666653). ClinVar contains an entry for this variant (Variation ID: 602). 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 with a positive predictive value of 80%. Experimental studies have shown that this missense change affects PAH function (PMID: 8304187, 9799096, 10479481). For these reasons, this variant has been classified as Pathogenic. -
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
Variant summary: PAH c.776C>T (p.Ala259Val) results in a non-conservative amino acid change located in the aromatic amino acid hydroxylase, C-terminal domain (IPR019774) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251340 control chromosomes (gnomAD). c.776C>T has been reported in the literature in multiple individuals affected with Phenylalanine Hydroxylase Deficiency (Phenylketonuria) (e.g. Koch_1997, Benit_1999, Jeannesson-Thivisol_2015). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function and found the variant results in <5% of normal activity (e.g. Benit_1999). The following publications have been ascertained in the context of this evaluation (PMID: 10479481, 26666653, 9169088). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic and likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
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not provided Other:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at