chr19-50402022-G-A

Variant names:

• chr19-50402022-G-A
• rs753299061
• NM_002691.4:c.487G>A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_002691.4(POLD1):​c.487G>A​(p.Asp163Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,808 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/23 in silico tools predict 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. D163Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.75

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

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.17686751).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLD1	NM_002691.4	c.487G>A	p.Asp163Asn	missense_variant	Exon 5 of 27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.487G>A	p.Asp163Asn	missense_variant	Exon 5 of 27	1	NM_002691.4	ENSP00000406046.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251206 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461808 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727224

Gnomad4 AFR exome AF: 0.00 AC: 0 AN: 33476

Gnomad4 AMR exome AF: 0.00 AC: 0 AN: 44724

Gnomad4 ASJ exome AF: 0.00 AC: 0 AN: 26128

Gnomad4 EAS exome AF: 0.00 AC: 0 AN: 39698

Gnomad4 SAS exome AF: 0.0000116 AC: 1 AN: 86244

Gnomad4 FIN exome AF: 0.00 AC: 0 AN: 53406

Gnomad4 NFE exome AF: 0.00 AC: 0 AN: 1111972

Gnomad4 Remaining exome AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:1

Apr 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 163 of the POLD1 protein (p.Asp163Asn). This variant is present in population databases (rs753299061, gnomAD 0.003%). 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: 1354539). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.66
CADD	Benign	21
DANN	Benign	0.85
DEOGEN2	Benign	0.16	T;.;.;.;T
Eigen	Benign	-0.54
Eigen_PC	Benign	-0.48
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.82	.;.;T;T;T
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.18	T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.79	N;.;.;.;N
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-1.1	N;.;.;.;.
REVEL	Benign	0.084
Sift	Benign	0.44	T;.;.;.;.
Sift4G	Benign	0.41	T;T;T;T;T
Polyphen		0.0	B;.;.;.;B
Vest4		0.26
MutPred		0.34		Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);
MVP		0.42
MPC		0.24
ClinPred		0.18	T
GERP RS		3.5
Varity_R		0.16
gMVP		0.43
Mutation Taster		=80/20	polymorphism

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: rs753299061; hg19: chr19-50905279;