19-50402703-G-C

Variant names:

• chr19-50402703-G-C
• rs777944185
• NM_002691.4:c.932G>C

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.932G>C​(p.Arg311Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000138 in 1,446,690 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R311C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: POLD1 NM_002691.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.95
• 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, 0.97

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLD1	NM_002691.4	c.932G>C	p.Arg311Pro	missense_variant	Exon 8 of 27	ENST00000440232.7	NP_002682.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLD1	ENST00000440232.7	c.932G>C	p.Arg311Pro	missense_variant	Exon 8 of 27	1	NM_002691.4	ENSP00000406046.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1446690 Hom.: 0 Cov.: 34 AF XY: 0.00000279 AC XY: 2 AN XY: 716814

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33154

American (AMR) AF: 0.00 AC: 0 AN: 44226

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25912

East Asian (EAS) AF: 0.00 AC: 0 AN: 39226

South Asian (SAS) AF: 0.0000117 AC: 1 AN: 85590

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52558

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4614

European-Non Finnish (NFE) AF: 9.07e-7 AC: 1 AN: 1101932

Other (OTH) AF: 0.00 AC: 0 AN: 59478

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.038550), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 05, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R311P variant (also known as c.932G>C), located in coding exon 7 of the POLD1 gene, results from a G to C substitution at nucleotide position 932. The arginine at codon 311 is replaced by proline, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D;.;.;D
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Pathogenic	0.99	.;.;D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Benign	-0.72	T
MutationAssessor	Pathogenic	3.7	H;.;.;H
PhyloP100		6.9
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-6.9	D;.;.;.
REVEL	Uncertain	0.50
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.94
MutPred		0.80		Gain of loop (P = 0.069);Gain of loop (P = 0.069);Gain of loop (P = 0.069);Gain of loop (P = 0.069);
MVP		0.71
MPC		0.91
ClinPred		0.99	D
GERP RS		2.3
Varity_R		0.99
gMVP		0.94
Mutation Taster		=18/82	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs777944185; hg19: chr19-50905960;