NM_002691.4:c.2978C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP3BP6

The NM_002691.4(POLD1):​c.2978C>T​(p.Thr993Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000083 in 1,565,678 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T993A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)
Exomes 𝑓: 0.0000085 ( 0 hom. )

Consequence

POLD1
NM_002691.4 missense

Scores

3
7
9

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 2.28

Publications

1 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.772
BP6
Variant 19-50416634-C-T is Benign according to our data. Variant chr19-50416634-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 408033.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLD1NM_002691.4 linkc.2978C>T p.Thr993Met missense_variant Exon 24 of 27 ENST00000440232.7 NP_002682.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLD1ENST00000440232.7 linkc.2978C>T p.Thr993Met missense_variant Exon 24 of 27 1 NM_002691.4 ENSP00000406046.1
ENSG00000142539ENST00000599632.1 linkc.185C>T p.Thr62Met missense_variant Exon 3 of 10 5 ENSP00000473233.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152180
Hom.:
0
Cov.:
34
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000175
AC:
3
AN:
171192
AF XY:
0.0000320
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000776
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000277
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000849
AC:
12
AN:
1413498
Hom.:
0
Cov.:
35
AF XY:
0.00000714
AC XY:
5
AN XY:
699876
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32322
American (AMR)
AF:
0.00
AC:
0
AN:
38402
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25342
East Asian (EAS)
AF:
0.0000540
AC:
2
AN:
37064
South Asian (SAS)
AF:
0.0000124
AC:
1
AN:
80864
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
43952
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5166
European-Non Finnish (NFE)
AF:
0.00000824
AC:
9
AN:
1091698
Other (OTH)
AF:
0.00
AC:
0
AN:
58688
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00000657
AC:
1
AN:
152180
Hom.:
0
Cov.:
34
AF XY:
0.0000135
AC XY:
1
AN XY:
74336
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000284
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000848
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1
Dec 22, 2022
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) -

Colorectal cancer, susceptibility to, 10 Uncertain:1
Nov 25, 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 methionine, which is neutral and non-polar, at codon 993 of the POLD1 protein (p.Thr993Met). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 408033). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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 Benign:1
May 12, 2025
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.23
T
BayesDel_noAF
Benign
-0.37
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.70
D;.;.;D
Eigen
Uncertain
0.22
Eigen_PC
Benign
0.097
FATHMM_MKL
Uncertain
0.79
D
LIST_S2
Uncertain
0.97
.;.;D;D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.77
D;D;D;D
MetaSVM
Benign
-1.1
T
MutationAssessor
Pathogenic
3.0
M;.;.;M
PhyloP100
2.3
PrimateAI
Pathogenic
0.92
D
PROVEAN
Uncertain
-3.5
D;.;.;.
REVEL
Benign
0.17
Sift
Benign
0.055
T;.;.;.
Sift4G
Benign
0.066
T;T;T;T
Polyphen
0.84
P;.;.;P
Vest4
0.69
MutPred
0.52
Loss of methylation at K992 (P = 0.0298);.;.;Loss of methylation at K992 (P = 0.0298);
MVP
0.73
MPC
1.6
ClinPred
0.92
D
GERP RS
2.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.2
Varity_R
0.37
gMVP
0.45
Mutation Taster
=37/63
disease causing

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

Other links and lift over

dbSNP: rs762280958; hg19: chr19-50919891; API