19-50402736-G-T

Position:

• chr19-50402736-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_002691.4(POLD1):​c.965G>T​(p.Arg322Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000000696 in 1,437,288 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. R322C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.91

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.821

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.965G>T	p.Arg322Leu	missense_variant	8/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.965G>T	p.Arg322Leu	missense_variant	8/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.96e-7 AC: 1 AN: 1437288 Hom.: 0 Cov.: 34 AF XY: 0.00000141 AC XY: 1 AN XY: 710568

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.0000169

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

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

Jun 13, 2017

In summary, this variant has uncertain impact on POLD1 function. The available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with a POLD1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with leucine at codon 322 of the POLD1 protein (p.Arg322Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 28, 2021

The p.R322L variant (also known as c.965G>T), located in coding exon 7 of the POLD1 gene, results from a G to T substitution at nucleotide position 965. The arginine at codon 322 is replaced by leucine, an amino acid with dissimilar 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	0.98
BayesDel_addAF	Uncertain	0.059	T
BayesDel_noAF	Benign	-0.15
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.50	T;.;.;T
Eigen	Benign	0.13
Eigen_PC	Benign	0.091
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Benign	0.053	D
MetaRNN	Pathogenic	0.82	D;D;D;D
MetaSVM	Benign	-1.2	T
MutationAssessor	Uncertain	2.5	M;.;.;M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-6.7	D;.;.;.
REVEL	Benign	0.23
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Benign	0.15	T;T;T;T
Polyphen		0.58	P;.;.;P
Vest4		0.76
MutPred		0.66		Gain of catalytic residue at R322 (P = 0.0062);Gain of catalytic residue at R322 (P = 0.0062);Gain of catalytic residue at R322 (P = 0.0062);Gain of catalytic residue at R322 (P = 0.0062);
MVP		0.65
MPC		0.84
ClinPred		0.99	D
GERP RS		2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.94
gMVP		0.87

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: rs980303681; hg19: chr19-50905993;