19-50398953-C-G

Position:

• chr19-50398953-C-G

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_002691.4(POLD1):​c.102C>G​(p.Phe34Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000628 in 1,433,610 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000063 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -3.17

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 -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.14282814).
• BS2: High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLD1	NM_002691.4	c.102C>G	p.Phe34Leu	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.102C>G	p.Phe34Leu	missense_variant	2/27	1	NM_002691.4	ENSP00000406046	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000628 AC: 9 AN: 1433610 Hom.: 0 Cov.: 33 AF XY: 0.00000282 AC XY: 2 AN XY: 710314

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: 0.00000819

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Dec 23, 2023

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 34 of the POLD1 protein (p.Phe34Leu). 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: 841478). 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 leucine 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 01, 2022

The p.F34L variant (also known as c.102C>G), located in coding exon 1 of the POLD1 gene, results from a C to G substitution at nucleotide position 102. The phenylalanine at codon 34 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. 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	0.94
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.50
CADD	Benign	2.5
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.68	D;.;.;.;D;.
Eigen	Benign	-0.95
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.064	N
LIST_S2	Benign	0.67	.;.;T;T;T;T
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.14	T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.69	N;.;.;.;N;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-3.4	D;.;.;.;.;.
REVEL	Benign	0.17
Sift	Benign	0.098	T;.;.;.;.;.
Sift4G	Benign	0.18	T;T;D;T;T;D
Polyphen		0.30	B;.;.;.;B;.
Vest4		0.26
MutPred		0.33		Loss of helix (P = 0.0795);Loss of helix (P = 0.0795);Loss of helix (P = 0.0795);Loss of helix (P = 0.0795);Loss of helix (P = 0.0795);Loss of helix (P = 0.0795);
MVP		0.44
MPC		0.22
ClinPred		0.31	T
GERP RS		-5.0
Varity_R		0.16
gMVP		0.41

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: rs754716741; hg19: chr19-50902210;