NM_002691.4:c.1918A>G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_002691.4(POLD1):c.1918A>G(p.Thr640Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000744 in 1,612,998 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T640I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

POLD1
NM_002691.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 6.43

Publications

6 publications found

Variant links:

Genes affected

POLD1 (HGNC:9175): (DNA polymerase delta 1, catalytic subunit) This gene encodes the 125-kDa catalytic subunit of DNA polymerase delta. DNA polymerase delta possesses both polymerase and 3' to 5' exonuclease activity and plays a critical role in DNA replication and repair. Alternatively spliced transcript variants have been observed for this gene, and a pseudogene of this gene is located on the long arm of chromosome 6. [provided by RefSeq, Mar 2012]

POLD1 Gene-Disease associations (from GenCC):

POLD1-related polyposis and colorectal cancer syndrome
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
colorectal cancer, susceptibility to, 10
Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
mandibular hypoplasia-deafness-progeroid syndrome
Inheritance: AD, AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, Ambry Genetics, Orphanet, G2P
Polymerase proofreading-related adenomatous polyposis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
immunodeficiency 120
Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
non-severe combined immunodeficiency due to polymerase delta deficiency
Inheritance: AR Classification: LIMITED Submitted by: ClinGen

POLD1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.37811768).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLD1	NM_002691.4 link	c.1918A>G	p.Thr640Ala	missense_variant	Exon 16 of 27	ENST00000440232.7	NP_002682.2	P28340A0A024R4F4Q59FA0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7 link	c.1918A>G	p.Thr640Ala	missense_variant	Exon 16 of 27	1	NM_002691.4	ENSP00000406046.1		P28340

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152086

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000199

AC:

AN:

251036

AF XY:

0.0000295

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000548

AC:

AN:

1460794

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

726790

show subpopulations

African (AFR)

AF:

0.000179

AC:

AN:

33460

American (AMR)

AF:

0.00

AC:

AN:

44712

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86234

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53226

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111200

Other (OTH)

AF:

0.0000166

AC:

AN:

60372

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74400

show subpopulations

African (AFR)

AF:

0.0000964

AC:

AN:

41512

American (AMR)

AF:

0.00

AC:

AN:

15294

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5168

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.563

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000491

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Feb 28, 2020

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 31, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 29056344, 20951805) -

POLD1-related disorder

Uncertain:1

Jan 25, 2023

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The POLD1 c.1918A>G variant is predicted to result in the amino acid substitution p.Thr640Ala. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.031% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/19-50912404-A-G). In ClinVar, this variant is interpreted as uncertain (https://preview.ncbi.nlm.nih.gov/clinvar/variation/537065/). Although we suspect that this variant may be benign, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Colorectal cancer, susceptibility to, 10;C3715192:Mandibular hypoplasia-deafness-progeroid syndrome

Uncertain:1

Oct 19, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Colorectal cancer, susceptibility to, 10

Uncertain:1

Jan 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 640 of the POLD1 protein (p.Thr640Ala). This variant is present in population databases (rs201212113, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with POLD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 537065). 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 not expected to disrupt POLD1 protein function with a negative predictive value of 80%. 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. -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jan 07, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.T640A variant (also known as c.1918A>G), located in coding exon 15 of the POLD1 gene, results from an A to G substitution at nucleotide position 1918. The threonine at codon 640 is replaced by alanine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.81

BayesDel_addAF

Benign

-0.22

BayesDel_noAF

Benign

-0.25

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.37

T;.;.;T

Eigen

Uncertain

0.41

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.90

.;.;D;D

M_CAP

Benign

0.073

MetaRNN

Benign

0.38

T;T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Uncertain

2.8

M;.;.;M

PhyloP100

6.4

PrimateAI

Uncertain

0.63

PROVEAN

Pathogenic

-5.0

D;.;.;.

REVEL

Benign

0.20

Sift

Uncertain

0.0010

D;.;.;.

Sift4G

Uncertain

0.0040

D;D;D;D

Polyphen

0.90

P;.;.;P

Vest4

0.61

MVP

0.62

MPC

1.6

ClinPred

0.84

GERP RS

3.4

Varity_R

0.80

gMVP

0.81

Mutation Taster

=15/85

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.16

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over