rs773665739

Positions:

• chr19-50409557-G-A
• chr19-50409557-G-C
• chr19-50409557-G-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_002691.4(POLD1):​c.2045G>A​(p.Arg682Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000178 in 1,461,144 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. R682W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 4.35

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]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.20391145).
• BS2: High AC in GnomAdExome4 at 26 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.2045G>A	p.Arg682Gln	missense_variant	17/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.2045G>A	p.Arg682Gln	missense_variant	17/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000160 AC: 4 AN: 249760 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135340

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000890

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461144 Hom.: 0 Cov.: 32 AF XY: 0.0000151 AC XY: 11 AN XY: 726916

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000894

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000927

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000117

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Carcinoma of colon Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The POLD1 p.Arg682Gln variant was not identified in the literature. The variant was identified in dbSNP (rs773665739) as “with uncertain significance allele” and ClinVar (classified as uncertain significance by Invitae). The variant was identified in control databases in 4 of 249,760 chromosomes at a frequency of 0.00002 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 3 of 34,564 chromosomes (freq: 0.00008) and European in 1 of 112,378 chromosomes (freq: 0.000009), while it was not observed in the African, Ashkenazi Jewish, East Asian, Finnish, Other or South Asian populations. The p.Arg682 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 27, 2020

In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 06, 2024

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 682 of the POLD1 protein (p.Arg682Gln). This variant is present in population databases (rs773665739, gnomAD 0.009%). 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: 408047). 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 30, 2023

The p.R682Q variant (also known as c.2045G>A), located in coding exon 16 of the POLD1 gene, results from a G to A substitution at nucleotide position 2045. The arginine at codon 682 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.53
CADD	Uncertain	26
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.18	T;.;.;T
Eigen	Benign	0.059
Eigen_PC	Benign	0.18
FATHMM_MKL	Uncertain	0.77	D
M_CAP	Benign	0.039	D
MetaRNN	Benign	0.20	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.6	L;.;.;L
MutationTaster	Benign	0.98	D
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-2.0	N;.;.;.
REVEL	Benign	0.036
Sift	Uncertain	0.011	D;.;.;.
Sift4G	Benign	0.083	T;T;T;T
Polyphen		0.15	B;.;.;B
Vest4		0.34
MutPred		0.46		Loss of MoRF binding (P = 0.0396);.;.;Loss of MoRF binding (P = 0.0396);
MVP		0.55
MPC		1.4
ClinPred		0.46	T
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.16
gMVP		0.37

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

Other links and lift over

dbSNP: rs773665739; hg19: chr19-50912814; COSMIC: COSV70953996; COSMIC: COSV70953996;