chr19-50408808-C-T

Position:

• chr19-50408808-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The ENST00000440232.7(POLD1):​c.1799C>T​(p.Thr600Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000161 in 1,613,854 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 (★★). Synonymous variant affecting the same amino acid position (i.e. T600T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: POLD1 ENST00000440232.7 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.08

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 Likely_benign. Variant got -2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.889
• BS2: High AC in GnomAdExome4 at 25 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.1799C>T	p.Thr600Ile	missense_variant	15/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.1799C>T	p.Thr600Ile	missense_variant	15/27	1	NM_002691.4	ENSP00000406046	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152208 Hom.: 0 Cov.: 32

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 AF: 0.0000171 AC: 25 AN: 1461646 Hom.: 0 Cov.: 34 AF XY: 0.0000124 AC XY: 9 AN XY: 727148

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: 0.0000225

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152208 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74348

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

Bravo AF: 0.00000756

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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 03, 2023

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 600 of the POLD1 protein (p.Thr600Ile). 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: 407979). 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. 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

Mar 13, 2024

The p.T600I variant (also known as c.1799C>T), located in coding exon 14 of the POLD1 gene, results from a C to T substitution at nucleotide position 1799. The threonine at codon 600 is replaced by isoleucine, 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	0.95
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	-0.010
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.40	T;.;.;T
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.89	D;D;D;D
MetaSVM	Benign	-0.78	T
MutationAssessor	Pathogenic	2.9	M;.;.;M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-6.0	D;.;.;.
REVEL	Uncertain	0.42
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		0.95	P;.;.;P
Vest4		0.89
MVP		0.78
MPC		1.7
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.91
gMVP		0.77

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: rs1060501810; hg19: chr19-50912065;