19-50398915-C-T

Position:

• chr19-50398915-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2 BP4_Moderate BS2

The NM_002691.4(POLD1):​c.64C>T​(p.Leu22Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000346 in 1,446,114 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.223

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 -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.12697622).
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.64C>T	p.Leu22Phe	missense_variant	2/27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.64C>T	p.Leu22Phe	missense_variant	2/27	1	NM_002691.4	ENSP00000406046	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000180 AC: 4 AN: 222676 Hom.: 0 AF XY: 0.00000837 AC XY: 1 AN XY: 119432

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000962

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000100

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000346 AC: 5 AN: 1446114 Hom.: 0 Cov.: 33 AF XY: 0.00000139 AC XY: 1 AN XY: 717824

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000473

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000120

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000181

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 14, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 35216513) -

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 14, 2023

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 22 of the POLD1 protein (p.Leu22Phe). This variant is present in population databases (rs779418268, gnomAD 0.01%). 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: 469374). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The phenylalanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.057
BayesDel_addAF	Benign	-0.40	T
BayesDel_noAF	Benign	-0.60
CADD	Benign	9.3
DANN	Benign	0.96
DEOGEN2	Benign	0.19	T;.;.;.;T;.
Eigen	Benign	-0.83
Eigen_PC	Benign	-0.83
FATHMM_MKL	Benign	0.64	D
LIST_S2	Benign	0.67	.;.;T;T;T;T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.13	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.55	N;.;.;.;N;.
MutationTaster	Benign	0.99	N
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-0.15	N;.;.;.;.;.
REVEL	Benign	0.018
Sift	Benign	0.093	T;.;.;.;.;.
Sift4G	Uncertain	0.054	T;T;D;T;T;D
Polyphen		0.0060	B;.;.;.;B;.
Vest4		0.14
MutPred		0.30		Gain of catalytic residue at L22 (P = 0.0611);Gain of catalytic residue at L22 (P = 0.0611);Gain of catalytic residue at L22 (P = 0.0611);Gain of catalytic residue at L22 (P = 0.0611);Gain of catalytic residue at L22 (P = 0.0611);Gain of catalytic residue at L22 (P = 0.0611);
MVP		0.19
MPC		0.20
ClinPred		0.028	T
GERP RS		0.96
Varity_R		0.028
gMVP		0.16

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: rs779418268; hg19: chr19-50902172; COSMIC: COSV70954044; COSMIC: COSV70954044;