chr12-132649801-GC-AA

Position:

• chr12-132649801-GC-AA

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006231.4(POLE):​c.3670_3671delGCinsTT​(p.Ala1224Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLE NM_006231.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1
• Conservation: PhyloP100: 2.48

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLE	NM_006231.4	c.3670_3671delGCinsTT	p.Ala1224Leu	missense_variant		ENST00000320574.10	NP_006222.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLE	ENST00000320574.10	c.3670_3671delGCinsTT	p.Ala1224Leu	missense_variant		1	NM_006231.4	ENSP00000322570.5

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: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	This sequence change replaces alanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1224 of the POLE protein (p.Ala1224Leu). This variant is present in population databases (no rsID available, gnomAD 0.01%). 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: 220928). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 09, 2024	In silico analysis indicates that this 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	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 17, 2018	- -

not specified Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 15, 2023	Variant summary: POLE c.3670_3671delinsTT (p.Ala1224Leu) results in a non-conservative amino acid change in the encoded protein sequence. Two of three in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 251358 control chromosomes (gnomAD), predominantly at a frequency of 0.00022 within the Non-Finnish European subpopulation in the gnomAD database. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 16 fold of the estimated maximal expected allele frequency for a pathogenic variant in POLE causing Colorectal Cancer (1.4e-05), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. To our knowledge, no occurrence of c.3670_3671delinsTT in individuals affected with Colorectal Cancer and no experimental evidence demonstrating its impact on protein function have been reported. Five ClinVar submitters have assessed the variant since 2014: all have classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely benign. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jan 12, 2017	The p.Ala1224Leu variant in POLE has not been previously reported in individuals with colorectal cancer. This variant is a result of a deletion of 2 nucleotides at positions c.3670 and c.3671 and an insertion of two different nucleotides at these positions and is not predicted to alter the protein reading-frame. This v ariant has been identified in 5/66478 of European chromosomes by the Exome Aggre gation Consortium (ExAC, http://exac.broadinstitute.org, note that the ExAC data base reports this variant as 2 separate substitutions in cis, c.3670G>T [rs36933 8222] and c.3671C>T [rs375208564]). Computational prediction tools and conservat ion analysis suggest that the p.Ala1224Leu variant may not impact the protein, t hough this information is not predictive enough to rule out pathogenicity. In su mmary, the clinical significance of the p.Ala1224Leu variant is uncertain. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 06, 2024

The c.3670_3671delGCinsTT variant (also known as p.A1224L), located in coding exon 30 of the POLE gene, results from an in-frame deletion of GC and insertion of TT at nucleotide positions 3670 to 3671. This results in the substitution of the alanine residue for a leucine residue at codon 1224, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be neutral by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Based on the available evidence, the clinical significance of this variant remains unclear. -

Colorectal cancer, susceptibility to, 12;C3554576:Facial dysmorphism-immunodeficiency-livedo-short stature syndrome;C5193036:Intrauterine growth retardation, metaphyseal dysplasia, adrenal hypoplasia congenita, genital anomalies, and immunodeficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Feb 25, 2022

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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: rs864622698; hg19: chr12-133226387;