chr19-50403070-G-T

Variant names:

• chr19-50403070-G-T
• rs1060501813
• NM_002691.4:c.988G>T

Variant summary

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

The NM_002691.4(POLD1):​c.988G>T​(p.Glu330*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000071 in 1,409,244 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 (★). Synonymous variant affecting the same amino acid position (i.e. E330E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: POLD1 NM_002691.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.20
• Publications: 1 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.988G>T	p.Glu330*	stop_gained	Exon 9 of 27	NP_002682.2
	POLD1	NM_001308632.1		c.988G>T	p.Glu330*	stop_gained	Exon 8 of 26	NP_001295561.1
	POLD1	NM_001256849.1		c.988G>T	p.Glu330*	stop_gained	Exon 9 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.988G>T	p.Glu330*	stop_gained	Exon 9 of 27	ENSP00000406046.1
	POLD1	ENST00000595904.6	TSL:1	c.988G>T	p.Glu330*	stop_gained	Exon 9 of 27	ENSP00000472445.1
	POLD1	ENST00000599857.7	TSL:1	c.988G>T	p.Glu330*	stop_gained	Exon 9 of 27	ENSP00000473052.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.10e-7 AC: 1 AN: 1409244 Hom.: 0 Cov.: 32 AF XY: 0.00000144 AC XY: 1 AN XY: 696280

⚠️ 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: 32054

American (AMR) AF: 0.00 AC: 0 AN: 37248

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25228

East Asian (EAS) AF: 0.00 AC: 0 AN: 36516

South Asian (SAS) AF: 0.00 AC: 0 AN: 80076

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49682

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5688

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1084436

Other (OTH) AF: 0.0000171 AC: 1 AN: 58316

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

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

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Glu330*) in the POLD1 gene. Missense variants that disrupt the 3'-5' exonuclease (proof-reading) activity of the POLD1 protein are associated with PPAP (polymerase proofreading–associated polyposis) (PMID: 23263490, 23447401). However, loss-of-function variants that result in an absent or severely disrupted POLD1 protein, and missense variants outside the exonuclease domain, are unlikely to be associated with PPAP. 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: 407986). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	49
DANN	Uncertain	1.0
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.95	D
PhyloP100		4.2
Vest4		0.91
GERP RS		3.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=6/194	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs1060501813; hg19: chr19-50906327;