NM_006231.4:c.5553-1G>A

Variant names:

• chr12-132638140-C-T
• rs1064796152
• NM_006231.4:c.5553-1G>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_006231.4(POLE):​c.5553-1G>A variant causes a splice acceptor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLE NM_006231.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.82

Genes affected

POLE (HGNC:9177): (DNA polymerase epsilon, catalytic subunit) This gene encodes the catalytic subunit of DNA polymerase epsilon. The enzyme is involved in DNA repair and chromosomal DNA replication. Mutations in this gene have been associated with colorectal cancer 12 and facial dysmorphism, immunodeficiency, livedo, and short stature. [provided by RefSeq, Sep 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.01836467 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-132638140-C-T is Pathogenic according to our data. Variant chr12-132638140-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 422998.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLE	NM_006231.4	c.5553-1G>A		splice_acceptor_variant, intron_variant	Intron 40 of 48	ENST00000320574.10	NP_006222.2
POLE	XM_011534795.4	c.5553-1G>A		splice_acceptor_variant, intron_variant	Intron 40 of 47		XP_011533097.1
POLE	XM_011534797.4	c.4632-1G>A		splice_acceptor_variant, intron_variant	Intron 32 of 39		XP_011533099.1
POLE	XM_011534802.4	c.2541-1G>A		splice_acceptor_variant, intron_variant	Intron 16 of 23		XP_011533104.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLE	ENST00000320574.10	c.5553-1G>A		splice_acceptor_variant, intron_variant	Intron 40 of 48	1	NM_006231.4	ENSP00000322570.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:1

Jan 04, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is denoted POLE c.5553-1G>A or IVS40-1G>A and consists of a G>A nucleotide substitution at the -1 position of intron 40 of the POLE gene. This variant destroys a canonical splice acceptor site and is predicted to cause abnormal gene splicing, leading to either an abnormal message that is subject to nonsense-mediated mRNA decay or to an abnormal protein product. This variant has not, to our knowledge, been published in the literature. Although missense variants located within the exonuclease domain of the POLE gene have been recognized as an underlying cause of Polymerase Proofreading-Associated Polyposis (PPAP), an autosomal dominant condition associated with polyposis and an increased risk for colon cancer (Palles 2013, Spier 2014), there are no data to support that loss-of-function variants, such as this one, confer the same cancer risks. Smith et al. (2013) identified a POLE frameshift variant in a 26 year old with a history of colorectal cancer, but no information about family history was provided. Therefore, based on current evidence, we consider POLE c.5553-1G>A to be a variant of uncertain significance with respect to cancer.A recessive disease associated with one POLE variant has been reported in the literature. In one large consanguineous family, 11 affected relatives with a syndrome called FILS (facial dysmorphism, immunodeficiency, livedo, and short stature) were all found to be homozygous for a POLE c.4444+3A>G, a splice variant which results in a small proportion (~10%) of normal POLE transcript (Pachlopnik Schmid 2012). In addition, an unrelated individual with a suspected chromosome instability syndrome was also found to be homozygous for POLE c.4444+3A>G (Thiffault 2015). We cannot assess whether the variant identified in the current patient would cause the same recessive disease. Individuals and family members of reproductive age may choose to consider assessment of potential reproductive risks. -

Aug 08, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 40 of the POLE gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in POLE are known to be pathogenic (PMID: 23230001, 25948378, 30503519). This variant has not been reported in the literature in individuals affected with POLE-related conditions. ClinVar contains an entry for this variant (Variation ID: 422998). 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 currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.47		Position offset: -2
DS_AL_spliceai		0.99		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1064796152; hg19: chr12-133214726;