1-45331434-G-C

Variant names:

• chr1-45331434-G-C
• rs587778540
• NM_001048174.2:c.1225C>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1 BP4

The NM_001048174.2(MUTYH):​c.1225C>G​(p.Arg409Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000752 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. R409L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.31
• Publications: 0 publications found

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]

MUTYH Gene-Disease associations (from GenCC):

• familial adenomatous polyposis 2

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen, G2P
• colorectal cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
• familial ovarian cancer

  Inheritance: AD, AR Classification: NO_KNOWN Submitted by: ClinGen
• hereditary breast carcinoma

  Inheritance: AD, AR Classification: NO_KNOWN Submitted by: ClinGen

ENSG00000288208 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 18 benign, 54 uncertain in NM_001048174.2
• BP4: Computational evidence support a benign effect (MetaRNN=0.26413202).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MUTYH	NM_001048174.2	c.1225C>G	p.Arg409Gly	missense_variant	Exon 13 of 16	ENST00000456914.7	NP_001041639.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MUTYH	ENST00000456914.7	c.1225C>G	p.Arg409Gly	missense_variant	Exon 13 of 16	1	NM_001048174.2	ENSP00000407590.2
ENSG00000288208	ENST00000671898.1	n.1813C>G		non_coding_transcript_exon_variant	Exon 17 of 21			ENSP00000499896.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461886 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 33

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 23, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals affected with MUTYH-related conditions. This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 437 of the MUTYH protein (p.Arg437Gly). This variant is not present in population databases (gnomAD no frequency). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Mar 30, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R437G variant (also known as c.1309C>G), located in coding exon 13 of the MUTYH gene, results from a C to G substitution at nucleotide position 1309. The arginine at codon 437 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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	0.11
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Benign	19
DANN	Benign	0.90
DEOGEN2	Uncertain	0.52	.;.;.;.;.;.;D;.;.;.;.;D
Eigen	Benign	-0.66
Eigen_PC	Benign	-0.65
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.88	.;.;D;.;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Benign	0.26	T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.0051	T
MutationAssessor	Benign	1.2	.;.;.;.;.;.;L;.;.;.;.;.
PhyloP100		2.3
PrimateAI	Benign	0.22	T
PROVEAN	Benign	-2.0	N;D;D;D;D;D;D;D;D;N;D;.
REVEL	Benign	0.29
Sift	Benign	0.12	T;D;T;D;D;D;T;T;D;T;T;.
Sift4G	Uncertain	0.041	D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		0.0010, 0.0040, 0.0020	.;.;.;.;.;.;B;B;.;.;B;.
Vest4		0.29
MutPred		0.48		.;.;.;.;.;.;.;.;.;.;Gain of helix (P = 0.0425);.;
MVP		0.89
MPC		0.19
ClinPred		0.26	T
GERP RS		1.0
Varity_R		0.20
gMVP		0.47
Mutation Taster		=72/28	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs587778540; hg19: chr1-45797106;