chr19-50416528-C-G

Position:

• chr19-50416528-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_002691.4(POLD1):​c.2953C>G​(p.Arg985Gly) 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. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. R985L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLD1 NM_002691.4 missense, splice_region
• Scores: Splicing: ADA: 0.0001641
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.95

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.2953C>G	p.Arg985Gly	missense_variant, splice_region_variant	23/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.2953C>G	p.Arg985Gly	missense_variant, splice_region_variant	23/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Colorectal cancer, susceptibility to, 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 21, 2020

Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with POLD1-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with glycine at codon 985 of the POLD1 protein (p.Arg985Gly). The arginine residue is weakly conserved and there is a moderate physicochemical difference between arginine and glycine. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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	0.23
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.50
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.77	D;.;.;D
Eigen	Benign	-0.38
Eigen_PC	Benign	-0.39
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Uncertain	0.20	D
MetaRNN	Uncertain	0.43	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.8	M;.;.;M
MutationTaster	Benign	0.67	N
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.0	D;.;.;.
REVEL	Benign	0.13
Sift	Benign	0.095	T;.;.;.
Sift4G	Benign	0.15	T;T;T;T
Polyphen		0.074	B;.;.;B
Vest4		0.41
MutPred		0.52		Gain of helix (P = 0.0425);.;.;Gain of helix (P = 0.0425);
MVP		0.45
MPC		1.5
ClinPred		0.99	D
GERP RS		0.85
Varity_R		0.59
gMVP		0.51

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00016
dbscSNV1_RF	Benign	0.15
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: rs780926432; hg19: chr19-50919785;