19-50408850-A-T

Variant names:

• chr19-50408850-A-T
• rs1555791790
• NM_002691.4:c.1841A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_002691.4(POLD1):​c.1841A>T​(p.His614Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging 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. H614Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.32
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.972

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLD1	NM_002691.4	c.1841A>T	p.His614Leu	missense_variant	Exon 15 of 27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.1841A>T	p.His614Leu	missense_variant	Exon 15 of 27	1	NM_002691.4	ENSP00000406046.1

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

Jan 29, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a POLD1-related disease. This sequence change replaces histidine with leucine at codon 614 of the POLD1 protein (p.His614Leu). The histidine residue is highly conserved and there is a moderate physicochemical difference between histidine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.14
CADD	Pathogenic	28
DANN	Uncertain	0.98
DEOGEN2	Benign	0.40	T;.;.;T
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	.;.;D;D
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Benign	-0.31	T
MutationAssessor	Pathogenic	4.9	H;.;.;H
PhyloP100		8.3
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-11	D;.;.;.
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0010	D;.;.;.
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		0.98	D;.;.;D
Vest4		0.87
MutPred		0.87		Loss of catalytic residue at H614 (P = 0.038);.;.;Loss of catalytic residue at H614 (P = 0.038);
MVP		0.79
MPC		1.8
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.87
gMVP		0.90
Mutation Taster		=9/91	disease causing

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

Other links and lift over

dbSNP: rs1555791790; hg19: chr19-50912107;