19-50407146-T-C

Position:

• chr19-50407146-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_002691.4(POLD1):​c.1658T>C​(p.Val553Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,060 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. V553I) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 30)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.39

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.42351228).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.1658T>C	p.Val553Ala	missense_variant	13/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.1658T>C	p.Val553Ala	missense_variant	13/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152060 Hom.: 0 Cov.: 30

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152060 Hom.: 0 Cov.: 30 AF XY: 0.0000135 AC XY: 1 AN XY: 74272

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: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000330 Hom.: 0

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

Dec 01, 2023

This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 553 of the POLD1 protein (p.Val553Ala). 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: 408014). 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

Feb 05, 2022

The p.V553A variant (also known as c.1658T>C), located in coding exon 12 of the POLD1 gene, results from a T to C substitution at nucleotide position 1658. The valine at codon 553 is replaced by alanine, an amino acid with 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	Pathogenic	0.91
BayesDel_addAF	Benign	-0.094	T
BayesDel_noAF	Benign	-0.37
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.37	T;.;.;T
Eigen	Benign	-0.090
Eigen_PC	Benign	-0.041
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.97	.;.;D;D
M_CAP	Benign	0.050	D
MetaRNN	Benign	0.42	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.6	M;.;.;M
MutationTaster	Benign	0.99	D
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.7	D;.;.;.
REVEL	Benign	0.17
Sift	Uncertain	0.011	D;.;.;.
Sift4G	Uncertain	0.0070	D;D;D;D
Polyphen		0.18	B;.;.;B
Vest4		0.50
MVP		0.58
MPC		1.5
ClinPred		0.99	D
GERP RS		4.0
Varity_R		0.62
gMVP		0.50

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: rs1060501822; hg19: chr19-50910403;