chr19-50403580-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_002691.4(POLD1):​c.1225C>T​(p.Arg409Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,638 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R409G) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

POLD1
NM_002691.4 missense

Scores

9
8
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 1.12

Publications

14 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: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLD1NM_002691.4 linkc.1225C>T p.Arg409Trp missense_variant Exon 10 of 27 ENST00000440232.7 NP_002682.2 P28340A0A024R4F4Q59FA0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLD1ENST00000440232.7 linkc.1225C>T p.Arg409Trp missense_variant Exon 10 of 27 1 NM_002691.4 ENSP00000406046.1 P28340

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251404
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
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:
0.00000274
AC:
4
AN:
1459638
Hom.:
0
Cov.:
30
AF XY:
0.00000413
AC XY:
3
AN XY:
726288
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33440
American (AMR)
AF:
0.0000224
AC:
1
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86210
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1109950
Other (OTH)
AF:
0.00
AC:
0
AN:
60324
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00117289), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.388
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:4
Sep 06, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 12, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Apr 19, 2023
Myriad Genetics, Inc.
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -

Jan 21, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 409 of the POLD1 protein (p.Arg409Trp). This variant is present in population databases (rs778135510, gnomAD 0.003%). This missense change has been observed in individual(s) with early onset colorectal cancer and polyposis (PMID: 26133394). ClinVar contains an entry for this variant (Variation ID: 486071). 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 expected to disrupt POLD1 protein function with a positive 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:2
Sep 02, 2024
Molecular Diagnostics Laboratory, Catalan Institute of Oncology
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM2_supporting c.1225C>T, located in exon 10 of the POLD1 gene, is predicted to result in the substitution of Arginine by Tryptophan at codon 409, p.(Arg409Trp). This variant is found in 1/236874 alleles at a frequency of 0.0004% in the gnomAD v2.1.1 database, non-cancer dataset (PM2_supporting). The SpliceAI algorithm predicts no significant impact on splicing and the REVEL meta-predictor score (0.44) for this variant is indeterminate regarding the effect that it may have on protein function according Pejaver 2022 thresholds (PMID: 36413997). To our knowledge, well-stablished functional studies have not been reported for this variant. It has been identified in individuals affected with colorectal cancer (internal data, Bellido 2016). Based on currently available information, c.1225C>T is classified as an uncertain significance variant according to POLD1 guidelines. Comments: variant reclassificada per IMPaCT. -

Aug 07, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R409W variant (also known as c.1225C>T), located in coding exon 9 of the POLD1 gene, results from a C to T substitution at nucleotide position 1225. The arginine at codon 409 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration was identified in an individual with microsatellite-stable colorectal cancer diagnosed at 32 (Bellido F et al. Genet. Med., 2016 Apr;18:325-32). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Dec 14, 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; Identified in patients with colorectal cancer and/or polyps (Bellido et al., 2016; Georgeson et al., 2022); This variant is associated with the following publications: (PMID: 20951805, 35668106, 34897210, 26133394) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Pathogenic
0.16
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.67
D;.;.;D
Eigen
Uncertain
0.44
Eigen_PC
Uncertain
0.26
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Pathogenic
1.0
.;.;D;D
M_CAP
Uncertain
0.22
D
MetaRNN
Pathogenic
0.99
D;D;D;D
MetaSVM
Benign
-0.68
T
MutationAssessor
Pathogenic
3.7
H;.;.;H
PhyloP100
1.1
PrimateAI
Uncertain
0.67
T
PROVEAN
Pathogenic
-7.9
D;.;.;.
REVEL
Uncertain
0.45
Sift
Pathogenic
0.0
D;.;.;.
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
D;.;.;D
Vest4
0.98
MutPred
0.95
Gain of ubiquitination at K414 (P = 0.0747);Gain of ubiquitination at K414 (P = 0.0747);Gain of ubiquitination at K414 (P = 0.0747);Gain of ubiquitination at K414 (P = 0.0747);
MVP
0.76
MPC
1.7
ClinPred
1.0
D
GERP RS
0.054
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.98
gMVP
0.99
Mutation Taster
=0/100
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: rs778135510; hg19: chr19-50906837; API