19-50406237-A-T

Position:

• chr19-50406237-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_002691.4(POLD1):​c.1298A>T​(p.Asp433Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.56

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.1298A>T	p.Asp433Val	missense_variant	11/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.1298A>T	p.Asp433Val	missense_variant	11/27	1	NM_002691.4	ENSP00000406046.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461806 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 727212

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 28, 2022

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; In silico analysis suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 20951805) -

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 25, 2023

This sequence change replaces aspartic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 433 of the POLD1 protein (p.Asp433Val). 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: 484391). 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%. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). 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

May 30, 2023

The p.D433V variant (also known as c.1298A>T), located in coding exon 10 of the POLD1 gene, results from an A to T substitution at nucleotide position 1298. The aspartic acid at codon 433 is replaced by valine, an amino acid with highly dissimilar properties. This amino acid position is well conserved in available vertebrate species. 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	0.28
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.38
CADD	Pathogenic	30
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.46	T;.;.;T
Eigen	Benign	0.11
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	.;.;D;D
M_CAP	Benign	0.043	D
MetaRNN	Uncertain	0.59	D;D;D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.6	M;.;.;M
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-5.4	D;.;.;.
REVEL	Benign	0.16
Sift	Uncertain	0.018	D;.;.;.
Sift4G	Uncertain	0.050	T;T;T;T
Polyphen		0.18	B;.;.;B
Vest4		0.56
MutPred		0.61		Loss of disorder (P = 0.0251);Loss of disorder (P = 0.0251);Loss of disorder (P = 0.0251);Loss of disorder (P = 0.0251);
MVP		0.55
MPC		1.8
ClinPred		0.98	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.67
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.54		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.54		Position offset: 14

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

Publications

LitVar

Other links and lift over

dbSNP: rs767560532; hg19: chr19-50909494;