rs786204113

chr1-45331228-G-Achr1-45331228-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001048174.2(MUTYH):c.1346C>T(p.Thr449Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000219 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T449K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000022 (0 hom.)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 7.32

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.859

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.1430C>T	p.Thr477Met	missense_variant	14/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.1346C>T	p.Thr449Met	missense_variant	14/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.1430C>T	p.Thr477Met	missense_variant	14/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.1346C>T	p.Thr449Met	missense_variant	14/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251488 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135920

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000219 AC: 32 AN: 1461886 Hom.: 0 Cov.: 32 AF XY: 0.0000289 AC XY: 21 AN XY: 727244

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.0000225

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 2 Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Sep 04, 2023	This missense variant replaces threonine with methionine at codon 477 of the MUTYH protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MUTYH-related disorders in the literature. This variant has been identified in 4/251488 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Nov 27, 2023	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 477 of the MUTYH protein (p.Thr477Met). This variant is present in population databases (rs767747402, gnomAD 0.003%). This missense change has been observed in individual(s) with colorectal adenomas (PMID: 18515411). This variant is also known as c.1421C>T (T474M). ClinVar contains an entry for this variant (Variation ID: 188159). 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 disruptive. 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	Baylor Genetics	Jul 06, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	May 17, 2018	- -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 01, 2023	This missense variant replaces threonine with methionine at codon 477 of the MUTYH protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MUTYH-related disorders in the literature. This variant has been identified in 4/251488 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 04, 2022	The p.T477M variant (also known as c.1430C>T), located in coding exon 14 of the MUTYH gene, results from a C to T substitution at nucleotide position 1430. The threonine at codon 477 is replaced by methionine, an amino acid with similar properties. This alteration, designated as p.T474M, was identified in one individual from a multiple adenoma cohort; however, the individual also carried two pathogenic MUTYH mutations and phase of the alterations (cis or trans) was not determined (Dallosso AR et al. Gut. 2008 Sep;57:1252-5). 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 12, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Co-occurred with two pathogenic MUTYH variants in an individual with colorectal cancer, multiple colorectal adenomas, and gastric antral adenomas (Dallosso et al., 2008); Also known as MUTYH Thr474Met; This variant is associated with the following publications: (PMID: 23108399, 18515411) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Pathogenic	0.21
Cadd	Uncertain	25
Dann	Uncertain	1.0
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	1.0	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.96	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.52	T
PROVEAN	Uncertain	-4.2	D;D;D;D;D;D;D;D;D;D;D;.
REVEL	Pathogenic	0.79
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D;D;D;D;.
Sift4G	Uncertain	0.0020	D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	.;.;.;.;.;.;D;D;.;.;D;.
Vest4		0.80
MutPred		0.56		.;.;.;.;.;.;.;.;.;.;Gain of sheet (P = 0.0827);.;
MVP		0.96
MPC		0.56
ClinPred		0.94	D
GERP RS		5.2
Varity_R		0.72
gMVP		0.55

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: rs767747402; hg19: chr1-45796900; COSMIC: COSV58343848; COSMIC: COSV58343848;