1-45332586-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_001048174.2(MUTYH):c.594C>G(p.Ile198Met) 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 pathogenic 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. I198V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.141

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_001048174.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.821

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.678C>G	p.Ile226Met	missense_variant	8/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.594C>G	p.Ile198Met	missense_variant	8/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.678C>G	p.Ile226Met	missense_variant	8/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.594C>G	p.Ile198Met	missense_variant	8/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 09, 2019

The p.I226M variant (also known as c.678C>G), located in coding exon 8 of the MUTYH gene, results from a C to G substitution at nucleotide position 678. The isoleucine at codon 226 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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	0.17
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
Cadd	Benign	11
Dann	Uncertain	0.99
Eigen	Benign	-0.28
Eigen_PC	Benign	-0.53
FATHMM_MKL	Benign	0.47	N
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.43	D
MutationTaster	Benign	0.60	D;D;D;D;D;N;N;N;N;N;N;N;N;N
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-2.8	D;D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.69
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0, 1.0	.;.;.;.;.;D;D;.;D;.;.;.
Vest4		0.86
MutPred		0.70		.;.;.;.;.;.;.;.;Gain of MoRF binding (P = 0.2302);.;.;.;
MVP		0.88
MPC		0.55
ClinPred		0.98	D
GERP RS		-8.8
Varity_R		0.86
gMVP		0.70

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.18		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: rs371875647; hg19: chr1-45798258;