19-50415724-G-T

Position:

• chr19-50415724-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.2718G>T​(p.Arg906Ser) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: POLD1 NM_002691.4 missense, splice_region
• Scores: Splicing: ADA: 0.9971
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.60

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]

POLD1 (HGNC:):

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, 0.79

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.2718G>T	p.Arg906Ser	missense_variant, splice_region_variant	22/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.2718G>T	p.Arg906Ser	missense_variant, splice_region_variant	22/27	1	NM_002691.4	ENSP00000406046.1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1340438 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 662136

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: 0.00

GnomAD4 genome Cov.: 30

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

Oct 09, 2023

This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 906 of the POLD1 protein (p.Arg906Ser). 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: 537080). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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

Sep 28, 2023

The p.R906S variant (also known as c.2718G>T) is located in coding exon 21 of the POLD1 gene. The arginine at codon 906 is replaced by serine, an amino acid with dissimilar properties. This change occurs in the first base pair of coding exon 21. 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	1.0
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Benign	0.41	T;.;.;T
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.79	D;D;D;D
MetaSVM	Benign	-0.83	T
MutationAssessor	Pathogenic	4.1	H;.;.;H
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.4	D;.;.;.
REVEL	Uncertain	0.34
Sift	Uncertain	0.0010	D;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		0.94	P;.;.;P
Vest4		0.66
MutPred		0.70		Gain of phosphorylation at R906 (P = 0.0362);.;.;Gain of phosphorylation at R906 (P = 0.0362);
MVP		0.55
MPC		1.7
ClinPred		1.0	D
GERP RS		2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7
Varity_R		0.78
gMVP		0.81

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.090		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: rs1555793133; hg19: chr19-50918981;