19-50415765-A-G

Position:

• chr19-50415765-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_002691.4(POLD1):​c.2759A>G​(p.Asp920Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000258 in 1,550,128 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 0.0000068 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.37

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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.884

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.2759A>G	p.Asp920Gly	missense_variant	22/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.2759A>G	p.Asp920Gly	missense_variant	22/27	1	NM_002691.4	ENSP00000406046	P1

Frequencies

GnomAD3 genomes AF: 0.00000678 AC: 1 AN: 147422 Hom.: 0 Cov.: 31

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: 0.0000150

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000214 AC: 3 AN: 1402706 Hom.: 0 Cov.: 33 AF XY: 0.00000288 AC XY: 2 AN XY: 694374

Gnomad4 AFR exome AF: 0.0000309

Gnomad4 AMR exome AF: 0.0000517

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000678 AC: 1 AN: 147422 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 71900

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000150

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.00000846 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 920 of the POLD1 protein (p.Asp920Gly). 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: 537124). 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 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:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 26, 2021

The p.D920G variant (also known as c.2759A>G), located in coding exon 21 of the POLD1 gene, results from an A to G substitution at nucleotide position 2759. The aspartic acid at codon 920 is replaced by glycine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. 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	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.060
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.40	T;.;.;T
Eigen	Uncertain	0.46
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Pathogenic	0.48	D
MetaRNN	Pathogenic	0.88	D;D;D;D
MetaSVM	Benign	-0.89	T
MutationAssessor	Pathogenic	3.0	M;.;.;M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-6.9	D;.;.;.
REVEL	Uncertain	0.41
Sift	Uncertain	0.0010	D;.;.;.
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.91
MutPred		0.81		Gain of MoRF binding (P = 0.0516);.;.;Gain of MoRF binding (P = 0.0516);
MVP		0.65
MPC		1.8
ClinPred		0.98	D
GERP RS		2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.86
gMVP		0.83

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs779041717; hg19: chr19-50919022;