Genetic Variant POLA2:p.Ile257Thr (chr11-65281017-T-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_002689.4(POLA2):c.770T>C(p.Ile257Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,904 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: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

POLA2
NM_002689.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.57

Variant links:

Genes affected

POLA2 (HGNC:30073): (DNA polymerase alpha 2, accessory subunit) Predicted to enable DNA binding activity. Involved in DNA replication, synthesis of RNA primer. Located in cytosol and nucleoplasm. Part of alpha DNA polymerase:primase complex. [provided by Alliance of Genome Resources, Apr 2022]

POLA2 links:

ENSG00000285816 (HGNC:):

ENSG00000285816 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLA2	NM_002689.4 link	c.770T>C	p.Ile257Thr	missense_variant	Exon 8 of 18	ENST00000265465.8	NP_002680.2	Q14181-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLA2	ENST00000265465.8 link	c.770T>C	p.Ile257Thr	missense_variant	Exon 8 of 18	1	NM_002689.4	ENSP00000265465.3		Q14181-1
ENSG00000285816	ENST00000649896.1 link	n.770T>C		non_coding_transcript_exon_variant	Exon 8 of 20			ENSP00000498025.1		A0A3B3ITS5

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

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:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251312

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135812

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1461704

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727136

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:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74358

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Dec 20, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.770T>C (p.I257T) alteration is located in exon 8 (coding exon 8) of the POLA2 gene. This alteration results from a T to C substitution at nucleotide position 770, causing the isoleucine (I) at amino acid position 257 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.47

BayesDel_addAF

Pathogenic

0.25

BayesDel_noAF

Pathogenic

0.22

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.75

Eigen

Uncertain

0.61

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.097

MetaRNN

Pathogenic

0.97

MetaSVM

Benign

-0.48

MutationAssessor

Pathogenic

3.4

PrimateAI

Uncertain

0.68

PROVEAN

Uncertain

-4.2

REVEL

Pathogenic

0.65

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0030

Polyphen

0.91

Vest4

0.95

MutPred

0.86

Loss of stability (P = 0.0131);

MVP

0.54

MPC

0.68

ClinPred

0.98

GERP RS

5.4

RBP_binding_hub_radar

0.92

RBP_regulation_power_radar

2.0

Varity_R

0.83

gMVP

0.83

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