19-50407037-T-C

Position:

• chr19-50407037-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_002691.4(POLD1):​c.1549T>C​(p.Tyr517His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,876 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y517C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.86

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2686203).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.1549T>C	p.Tyr517His	missense_variant	13/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.1549T>C	p.Tyr517His	missense_variant	13/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460876 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 726744

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

Alfa AF: 0.0000468 Hom.: 0

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

May 10, 2022

This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 517 of the POLD1 protein (p.Tyr517His). 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: 408080). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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

Jun 15, 2022

The p.Y517H variant (also known as c.1549T>C), located in coding exon 12 of the POLD1 gene, results from a T to C substitution at nucleotide position 1549. The tyrosine at codon 517 is replaced by histidine, an amino acid with 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	Benign	0.31
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.73	D;.;.;D
Eigen	Benign	-0.33
Eigen_PC	Benign	-0.36
FATHMM_MKL	Benign	0.30	N
LIST_S2	Uncertain	0.96	.;.;D;D
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.27	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Pathogenic	3.2	M;.;.;M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-3.0	D;.;.;.
REVEL	Benign	0.10
Sift	Uncertain	0.0080	D;.;.;.
Sift4G	Uncertain	0.027	D;D;D;D
Polyphen		0.0030	B;.;.;B
Vest4		0.32
MutPred		0.47		Loss of stability (P = 0.1202);Loss of stability (P = 0.1202);Loss of stability (P = 0.1202);Loss of stability (P = 0.1202);
MVP		0.58
MPC		1.1
ClinPred		0.83	D
GERP RS		1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.3
Varity_R		0.28
gMVP		0.59

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: rs1060501843; hg19: chr19-50910294;