1-45333442-C-T

Variant names:

• chr1-45333442-C-T
• rs773108803
• NM_001048174.2:c.235G>A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001048174.2(MUTYH):​c.235G>A​(p.Glu79Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 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. E79G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.476

Genes affected

MUTYH (HGNC:7527): (mutY DNA glycosylase) This gene encodes a DNA glycosylase involved in oxidative DNA damage repair. The enzyme excises adenine bases from the DNA backbone at sites where adenine is inappropriately paired with guanine, cytosine, or 8-oxo-7,8-dihydroguanine, a major oxidatively damaged DNA lesion. The protein is localized to the nucleus and mitochondria. This gene product is thought to play a role in signaling apoptosis by the introduction of single-strand breaks following oxidative damage. Mutations in this gene result in heritable predisposition to colorectal cancer, termed MUTYH-associated polyposis (MAP). Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2017]

ENSG00000288208 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 17 uncertain in NM_001048174.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09916106).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MUTYH	NM_001048174.2	c.235G>A	p.Glu79Lys	missense_variant	Exon 3 of 16	ENST00000456914.7	NP_001041639.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MUTYH	ENST00000456914.7	c.235G>A	p.Glu79Lys	missense_variant	Exon 3 of 16	1	NM_001048174.2	ENSP00000407590.2
ENSG00000288208	ENST00000671898.1	n.823G>A		non_coding_transcript_exon_variant	Exon 7 of 21			ENSP00000499896.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 2 Uncertain:1

Sep 21, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The lysine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 823159). This variant has not been reported in the literature in individuals affected with MUTYH-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 107 of the MUTYH protein (p.Glu107Lys). -

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 15, 2018

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E107K variant (also known as c.319G>A), located in coding exon 3 of the MUTYH gene, results from a G to A substitution at nucleotide position 319. The glutamic acid at codon 107 is replaced by lysine, 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 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	0.078
BayesDel_addAF	Uncertain	0.035	T
BayesDel_noAF	Benign	-0.19
CADD	Benign	15
DANN	Benign	0.80
DEOGEN2	Benign	0.14	.;.;.;.;.;T;.;.;.;T;T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.23	N
LIST_S2	Uncertain	0.90	.;D;.;D;D;D;D;D;D;D;D;T
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.099	T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.61	T
MutationAssessor	Uncertain	2.0	.;.;.;.;.;M;.;.;.;.;.;.
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-0.90	N;N;N;N;N;N;N;N;N;N;N;N
REVEL	Benign	0.28
Sift	Benign	0.64	T;T;T;T;T;T;T;T;T;T;T;T
Sift4G	Benign	0.46	T;T;T;T;T;T;T;T;T;T;T;T
Polyphen		0.0	.;.;.;.;.;B;B;.;B;.;.;.
Vest4		0.13
MutPred		0.46		.;.;.;.;.;.;.;.;Gain of MoRF binding (P = 0.0056);.;.;.;
MVP		0.71
MPC		0.13
ClinPred		0.027	T
GERP RS		2.0
Varity_R		0.072
gMVP		0.49

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs773108803; hg19: chr1-45799114;