Genetic Variant PPA2:p.Phe331Cys (chr4-105369738-A-C) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_176869.3(PPA2):c.992T>G(p.Phe331Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000625 in 1,440,312 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 (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

PPA2
NM_176869.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.14

Variant links:

Genes affected

PPA2 (HGNC:28883): (inorganic pyrophosphatase 2) The protein encoded by this gene is localized to the mitochondrion, is highly similar to members of the inorganic pyrophosphatase (PPase) family, and contains the signature sequence essential for the catalytic activity of PPase. PPases catalyze the hydrolysis of pyrophosphate to inorganic phosphate, which is important for the phosphate metabolism of cells. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008]

PPA2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.763

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PPA2	NM_176869.3 link	c.992T>G	p.Phe331Cys	missense_variant	Exon 12 of 12	ENST00000341695.10	NP_789845.1	Q9H2U2-1
PPA2	NM_006903.4 link	c.905T>G	p.Phe302Cys	missense_variant	Exon 11 of 11		NP_008834.3	Q9H2U2-3
PPA2	NM_176866.2 link	c.686T>G	p.Phe229Cys	missense_variant	Exon 8 of 8		NP_789842.2	Q9H2U2-6
PPA2	NM_176867.3 link	c.494T>G	p.Phe165Cys	missense_variant	Exon 6 of 6		NP_789843.2	Q9H2U2-4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PPA2	ENST00000341695.10 link	c.992T>G	p.Phe331Cys	missense_variant	Exon 12 of 12	1	NM_176869.3	ENSP00000343885.5		Q9H2U2-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251158

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135720

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000625

AC:

AN:

1440312

Hom.:

Cov.:

AF XY:

0.00000697

AC XY:

AN XY:

717650

show subpopulations

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:

0.00000732

Gnomad4 OTH exome

AF:

0.0000167

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000227

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Mar 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 331 of the PPA2 protein (p.Phe331Cys). This variant is present in population databases (rs371782506, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with PPA2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.56

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Benign

0.32

T;.;.;.

Eigen

Uncertain

0.59

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.94

LIST_S2

Benign

0.79

T;T;T;T

M_CAP

Benign

0.041

MetaRNN

Pathogenic

0.76

D;D;D;D

MetaSVM

Benign

-0.67

MutationAssessor

Uncertain

2.0

M;.;.;.

PrimateAI

Uncertain

0.62

PROVEAN

Pathogenic

-4.6

D;D;D;D

REVEL

Uncertain

0.37

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0010

D;D;D;D

Polyphen

1.0

D;D;D;.

Vest4

0.70

MVP

0.79

MPC

0.59

ClinPred

0.96

GERP RS

5.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.43

gMVP

0.85

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over