19-50399044-G-C

Variant names:

• chr19-50399044-G-C
• rs975951740
• NM_002691.4:c.193G>C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BP6

The NM_002691.4(POLD1):​c.193G>C​(p.Val65Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000171 in 1,400,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V65A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 0.0280
• Publications: 3 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_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.049184024).
• BP6: Variant 19-50399044-G-C is Benign according to our data. Variant chr19-50399044-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 537055.

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.193G>C	p.Val65Leu	missense	Exon 2 of 27	NP_002682.2
	POLD1	NM_001308632.1		c.193G>C	p.Val65Leu	missense	Exon 1 of 26	NP_001295561.1
	POLD1	NM_001256849.1		c.193G>C	p.Val65Leu	missense	Exon 2 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.193G>C	p.Val65Leu	missense	Exon 2 of 27	ENSP00000406046.1
	POLD1	ENST00000595904.6	TSL:1	c.193G>C	p.Val65Leu	missense	Exon 2 of 27	ENSP00000472445.1
	POLD1	ENST00000599857.7	TSL:1	c.193G>C	p.Val65Leu	missense	Exon 2 of 27	ENSP00000473052.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000171 AC: 24 AN: 1400860 Hom.: 0 Cov.: 33 AF XY: 0.0000145 AC XY: 10 AN XY: 691126

African (AFR) AF: 0.0000629 AC: 2 AN: 31798

American (AMR) AF: 0.00 AC: 0 AN: 35828

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25190

East Asian (EAS) AF: 0.00 AC: 0 AN: 36104

South Asian (SAS) AF: 0.00 AC: 0 AN: 79326

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49582

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4784

European-Non Finnish (NFE) AF: 0.0000204 AC: 22 AN: 1080162

Other (OTH) AF: 0.00 AC: 0 AN: 58086

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

May 31, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Colorectal cancer, susceptibility to, 10 Uncertain:1

Oct 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 65 of the POLD1 protein (p.Val65Leu). 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: 537055). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt POLD1 protein function with a negative predictive value of 80%. 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 Benign:1

Mar 28, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.080
BayesDel_addAF	Benign	-0.38	T
BayesDel_noAF	Benign	-0.78
CADD	Benign	1.4
DANN	Benign	0.73
DEOGEN2	Benign	0.15	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.077	N
LIST_S2	Benign	0.66	T
M_CAP	Benign	0.0056	T
MetaRNN	Benign	0.049	T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	0.0	N
PhyloP100		0.028
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-0.45	N
REVEL	Benign	0.048
Sift	Benign	0.69	T
Sift4G	Benign	0.38	T
Polyphen		0.0010	B
Vest4		0.061
MutPred		0.19		Gain of sheet (P = 0.1208)
MVP		0.19
MPC		0.18
ClinPred		0.013	T
GERP RS		-0.011
PromoterAI		0.0055	Neutral
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.0
Varity_R		0.023
gMVP		0.14
Mutation Taster		=97/3	polymorphism

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: rs975951740; hg19: chr19-50902301;