NM_002691.4:c.1891G>T

Variant names:

• chr19-50408900-G-T
• rs1555791808
• NM_002691.4:c.1891G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_002691.4(POLD1):​c.1891G>T​(p.Gly631Cys) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. 2/3 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. G631D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLD1 NM_002691.4 missense, splice_region
• Scores: Splicing: ADA: 0.02154
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.76
• Publications: 0 publications found

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]

POLD1 Gene-Disease associations (from GenCC):

• POLD1-related polyposis and colorectal cancer syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• colorectal cancer, susceptibility to, 10

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
• mandibular hypoplasia-deafness-progeroid syndrome

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, Ambry Genetics, Orphanet, G2P
• Polymerase proofreading-related adenomatous polyposis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• immunodeficiency 120

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• non-severe combined immunodeficiency due to polymerase delta deficiency

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002691.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POLD1	NM_002691.4	MANE Select	c.1891G>T	p.Gly631Cys	missense splice_region	Exon 15 of 27	NP_002682.2
	POLD1	NM_001308632.1		c.1969G>T	p.Gly657Cys	missense splice_region	Exon 14 of 26	NP_001295561.1
	POLD1	NM_001256849.1		c.1891G>T	p.Gly631Cys	missense splice_region	Exon 15 of 27	NP_001243778.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POLD1	ENST00000440232.7	TSL:1 MANE Select	c.1891G>T	p.Gly631Cys	missense splice_region	Exon 15 of 27	ENSP00000406046.1
	POLD1	ENST00000595904.6	TSL:1	c.1969G>T	p.Gly657Cys	missense splice_region	Exon 15 of 27	ENSP00000472445.1
	POLD1	ENST00000599857.7	TSL:1	c.1891G>T	p.Gly631Cys	missense splice_region	Exon 15 of 27	ENSP00000473052.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

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

Aug 02, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine with cysteine at codon 631 of the POLD1 protein (p.Gly631Cys). The glycine residue is moderately conserved and there is a large physicochemical difference between glycine and cysteine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with POLD1-related conditions. 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: "Probably Damaging"; Align-GVGD: "Class C15"). 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.084	T
BayesDel_noAF	Benign	-0.36
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Benign	0.29	T
Eigen	Benign	0.082
Eigen_PC	Benign	0.12
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.82	T
M_CAP	Benign	0.044	D
MetaRNN	Uncertain	0.67	D
MetaSVM	Benign	-1.0	T
MutationAssessor	Pathogenic	3.7	H
PhyloP100		4.8
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-3.2	D
REVEL	Benign	0.10
Sift	Benign	0.033	D
Sift4G	Uncertain	0.032	D
Polyphen		0.052	B
Vest4		0.62
MutPred		0.38		Loss of disorder (P = 0.0377)
MVP		0.61
MPC		1.6
ClinPred		0.94	D
GERP RS		4.7
Varity_R		0.28
gMVP		0.72
Mutation Taster		=44/56	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.022
dbscSNV1_RF	Benign	0.18
SpliceAI score (max)		0.37		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.37		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1555791808; hg19: chr19-50912157;