chr19-50401993-CACCAGGTT-C

Position:

• chr19-50401993-CACCAGGTT-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_002691.4(POLD1):​c.464-5_466del variant causes a splice acceptor, coding sequence, intron change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLD1 NM_002691.4 splice_acceptor, coding_sequence, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.31

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.037605293 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLD1	NM_002691.4	c.464-5_466del		splice_acceptor_variant, coding_sequence_variant, intron_variant	5/27	ENST00000440232.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLD1	ENST00000440232.7	c.464-5_466del		splice_acceptor_variant, coding_sequence_variant, intron_variant	5/27	1	NM_002691.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 11, 2020

This sequence change affects an acceptor splice site in intron 4 of the POLD1 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. Missense variants that disrupt the 3'-5' exonuclease (proof-reading) activity of the POLD1 protein, are associated with an increased risk for colonic adenomatous polyps and colon cancer (PMID: 23263490, 23447401). However loss-of-function variants, which result in an absent or severely disrupted POLD1 protein, and missense variants outside the exonuclease domain are unlikely to be associated with polyposis or colon cancer. Without further clinical and genetic evidence, this variant has been classified as a Variant of Uncertain Significance. This variant has not been reported in the literature in individuals with POLD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 407958). This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1060501803; hg19: chr19-50905250;