19-50402741-G-C

Variant names:

• chr19-50402741-G-C
• rs1160832458
• NM_002691.4:c.970G>C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_002691.4(POLD1):​c.970G>C​(p.Gly324Arg) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: POLD1 NM_002691.4 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.09

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_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLD1	NM_002691.4	c.970G>C	p.Gly324Arg	missense_variant, splice_region_variant	Exon 8 of 27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.970G>C	p.Gly324Arg	missense_variant, splice_region_variant	Exon 8 of 27	1	NM_002691.4	ENSP00000406046.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

POLD1-related disorder Uncertain:1

Dec 05, 2019

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The POLD1 c.970G>C (p.Gly324Arg) variant is a missense variant. A literature search was performed for the gene, cDNA change, and amino acid change. No publications were found based on this search. The p.Gly324Arg variant is not found in the Genome Aggregation Database, in a region of good sequence coverage, so is presumed to be rare. The Gly324 residue maps to the exonuclease domain of the protein. Based on the limited evidence, the p.Gly324Arg variant is classified as a variant of unknown significance for POLD1-related disorders. -

Colorectal cancer, susceptibility to, 10 Uncertain:1

Mar 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 324 of the POLD1 protein (p.Gly324Arg). This variant also falls at the last nucleotide of exon 8, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). 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: 973296). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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 30, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G324R variant (also known as c.970G>C), located in coding exon 7 of the POLD1 gene, results from a G to C substitution at nucleotide position 970. The glycine at codon 324 is replaced by arginine, an amino acid with dissimilar properties. However, this change occurs in the last base pair of coding exon 7, which makes it likely to have some effect on normal mRNA splicing. This nucleotide position is highly conserved in available vertebrate species. This amino acid position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. In addition, as a missense substitution this is predicted to be inconclusive by in silico analysis. However, loss of function of POLD1 has not been established as a mechanism of disease. Based on the available evidence, 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	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.51	D;.;.;D
Eigen	Pathogenic	0.77
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.90	D;D;D;D
MetaSVM	Benign	-0.68	T
MutationAssessor	Pathogenic	3.7	H;.;.;H
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-7.8	D;.;.;.
REVEL	Uncertain	0.49
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.47
MutPred		0.86		Gain of solvent accessibility (P = 0.019);Gain of solvent accessibility (P = 0.019);Gain of solvent accessibility (P = 0.019);Gain of solvent accessibility (P = 0.019);
MVP		0.74
MPC		0.82
ClinPred		1.0	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.77		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.77		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs1160832458; hg19: chr19-50905998;