19-50407133-C-A

Position:

• chr19-50407133-C-A

Variant summary

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

The NM_002691.4(POLD1):​c.1645C>A​(p.Arg549Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,674 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 (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • 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: 2.53

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, 0.811

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.1645C>A	p.Arg549Ser	missense_variant	13/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.1645C>A	p.Arg549Ser	missense_variant	13/27	1	NM_002691.4	ENSP00000406046	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460674 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726636

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 04, 2019

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with POLD1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with serine at codon 549 of the POLD1 protein (p.Arg549Ser). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.37	T;.;.;T
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Pathogenic	1.0	.;.;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.81	D;D;D;D
MetaSVM	Benign	-0.73	T
MutationAssessor	Pathogenic	4.4	H;.;.;H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-5.4	D;.;.;.
REVEL	Uncertain	0.30
Sift	Uncertain	0.0010	D;.;.;.
Sift4G	Uncertain	0.033	D;D;D;D
Polyphen		0.99	D;.;.;D
Vest4		0.85
MutPred		0.64		Loss of MoRF binding (P = 0.0187);Loss of MoRF binding (P = 0.0187);Loss of MoRF binding (P = 0.0187);Loss of MoRF binding (P = 0.0187);
MVP		0.70
MPC		1.7
ClinPred		1.0	D
GERP RS		2.9
Varity_R		0.95
gMVP		0.92

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: rs775734510; hg19: chr19-50910390;