chr4-105369748-C-G

Variant names:

• chr4-105369748-C-G
• NM_176869.3:c.982G>C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_176869.3(PPA2):​c.982G>C​(p.Val328Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PPA2 NM_176869.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.216

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05521345).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PPA2	NM_176869.3	c.982G>C	p.Val328Leu	missense_variant	Exon 12 of 12	ENST00000341695.10	NP_789845.1
PPA2	NM_006903.4	c.895G>C	p.Val299Leu	missense_variant	Exon 11 of 11		NP_008834.3
PPA2	NM_176866.2	c.676G>C	p.Val226Leu	missense_variant	Exon 8 of 8		NP_789842.2
PPA2	NM_176867.3	c.484G>C	p.Val162Leu	missense_variant	Exon 6 of 6		NP_789843.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PPA2	ENST00000341695.10	c.982G>C	p.Val328Leu	missense_variant	Exon 12 of 12	1	NM_176869.3	ENSP00000343885.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Dec 09, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with PPA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 328 of the PPA2 protein (p.Val328Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
CADD	Benign	11
DANN	Benign	0.90
DEOGEN2	Benign	0.028	T;.;.;.
Eigen	Benign	-0.92
Eigen_PC	Benign	-0.96
FATHMM_MKL	Benign	0.061	N
LIST_S2	Benign	0.80	T;T;T;T
M_CAP	Benign	0.0063	T
MetaRNN	Benign	0.055	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L;.;.;.
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-0.67	N;N;N;N
REVEL	Benign	0.025
Sift	Benign	0.28	T;T;T;T
Sift4G	Benign	0.26	T;T;T;T
Polyphen		0.070	B;B;B;.
Vest4		0.17
MutPred		0.27		Loss of sheet (P = 0.0817);.;.;.;
MVP		0.15
MPC		0.095
ClinPred		0.075	T
GERP RS		0.0081
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.035
gMVP		0.38

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr4-106290905;