12-132643948-C-A

Position:

• chr12-132643948-C-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_006231.4(POLE):​c.4179G>T​(p.Met1393Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,360 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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. M1393V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POLE NM_006231.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: -0.249

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.051762253).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLE	NM_006231.4	c.4179G>T	p.Met1393Ile	missense_variant	33/49	ENST00000320574.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLE	ENST00000320574.10	c.4179G>T	p.Met1393Ile	missense_variant	33/49	1	NM_006231.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251108 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135702

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461360 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726920

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 27, 2022	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Mar 20, 2017	This sequence change replaces methionine with isoleucine at codon 1393 of the POLE protein (p.Met1393Ile). The methionine residue is weakly conserved and there is a small physicochemical difference between methionine and isoleucine. This variant is present in population databases (rs778153462, ExAC 0.003%) but has not been reported in the literature in individuals with a POLE-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies. In summary, this variant is a rare missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2021

The p.M1393I variant (also known as c.4179G>T), located in coding exon 33 of the POLE gene, results from a G to T substitution at nucleotide position 4179. The methionine at codon 1393 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.37	T
BayesDel_noAF	Benign	-0.75
CADD	Benign	3.8
DANN	Benign	0.94
DEOGEN2	Benign	0.087	T;.
Eigen	Benign	-0.80
Eigen_PC	Benign	-0.70
FATHMM_MKL	Benign	0.36	N
LIST_S2	Benign	0.61	T;T
M_CAP	Benign	0.0075	T
MetaRNN	Benign	0.052	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.1	L;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-0.77	N;N
REVEL	Benign	0.031
Sift	Benign	0.14	T;T
Sift4G	Benign	0.062	T;T
Polyphen		0.0	B;B
Vest4		0.11
MutPred		0.47		Gain of catalytic residue at V1394 (P = 0.0202);.;
MVP		0.17
MPC		0.21
ClinPred		0.065	T
GERP RS		2.7
Varity_R		0.049
gMVP		0.17

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs778153462; hg19: chr12-133220534;