rs1555790271

Positions:

• chr19-50402691-T-C

Variant summary

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

The NM_002691.4(POLD1):​c.920T>C​(p.Ile307Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000000691 in 1,448,124 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I307M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.08

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, 0.798

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.920T>C	p.Ile307Thr	missense_variant	8/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.920T>C	p.Ile307Thr	missense_variant	8/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1448124 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 718150

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: 9.06e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Invitae

Sep 17, 2022

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. 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. ClinVar contains an entry for this variant (Variation ID: 537062). This variant has not been reported in the literature in individuals affected with POLD1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 307 of the POLD1 protein (p.Ile307Thr). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 22, 2023

The p.I307T variant (also known as c.920T>C), located in coding exon 7 of the POLD1 gene, results from a T to C substitution at nucleotide position 920. The isoleucine at codon 307 is replaced by threonine, an amino acid with similar properties. 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	0.71
BayesDel_addAF	Uncertain	0.088	D
BayesDel_noAF	Benign	-0.11
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.41	T;.;.;T
Eigen	Benign	0.13
Eigen_PC	Benign	0.12
FATHMM_MKL	Uncertain	0.78	D
M_CAP	Benign	0.042	D
MetaRNN	Pathogenic	0.80	D;D;D;D
MetaSVM	Benign	-1.2	T
MutationAssessor	Benign	1.9	M;.;.;M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-3.6	D;.;.;.
REVEL	Benign	0.22
Sift	Benign	0.088	T;.;.;.
Sift4G	Benign	0.072	T;T;T;T
Polyphen		0.65	P;.;.;P
Vest4		0.85
MutPred		0.60		Loss of catalytic residue at P309 (P = 0.0298);Loss of catalytic residue at P309 (P = 0.0298);Loss of catalytic residue at P309 (P = 0.0298);Loss of catalytic residue at P309 (P = 0.0298);
MVP		0.61
MPC		0.78
ClinPred		0.92	D
GERP RS		3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.50
gMVP		0.75

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: rs1555790271; hg19: chr19-50905948;