NM_001048174.2:c.49G>A

Variant names:

• chr1-45334457-C-T
• rs1553131489
• NM_001128425.2:c.91G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_001048174.2(MUTYH):​c.49G>A​(p.Ala17Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A17D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 0.368
• 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: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.088354915).
• BP6: Variant 1-45334457-C-T is Benign according to our data. Variant chr1-45334457-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 464739.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001048174.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MUTYH	NM_001128425.2	MANE Plus Clinical	c.91G>A	p.Ala31Thr	missense	Exon 2 of 16	NP_001121897.1
	MUTYH	NM_001048174.2	MANE Select	c.49G>A	p.Ala17Thr	missense	Exon 2 of 16	NP_001041639.1
	MUTYH	NM_012222.3		c.91G>A	p.Ala31Thr	missense	Exon 2 of 16	NP_036354.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MUTYH	ENST00000710952.2	MANE Plus Clinical	c.91G>A	p.Ala31Thr	missense	Exon 2 of 16	ENSP00000518552.2
	MUTYH	ENST00000456914.7	TSL:1 MANE Select	c.49G>A	p.Ala17Thr	missense	Exon 2 of 16	ENSP00000407590.2
	MUTYH	ENST00000372098.7	TSL:1	c.91G>A	p.Ala31Thr	missense	Exon 2 of 16	ENSP00000361170.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727232

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44716

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: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111998

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

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial adenomatous polyposis 2 Uncertain:2

Apr 03, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces alanine with threonine at codon 31 of the MUTYH protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified 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.

Jul 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 31 of the MUTYH protein (p.Ala31Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MUTYH-related conditions. ClinVar contains an entry for this variant (Variation ID: 464739). 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.

Hereditary cancer-predisposing syndrome Benign:1

Sep 09, 2025

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Benign	0.048	T
Eigen	Benign	-0.51
Eigen_PC	Benign	-0.51
FATHMM_MKL	Benign	0.066	N
LIST_S2	Benign	0.75	T
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.088	T
MetaSVM	Uncertain	-0.096	T
MutationAssessor	Benign	1.1	L
PhyloP100		0.37
PrimateAI	Benign	0.25	T
PROVEAN	Benign	0.030	N
REVEL	Benign	0.026
Sift	Uncertain	0.012	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.013	B
Vest4		0.43
MutPred		0.19		Gain of relative solvent accessibility (P = 0.0082)
MVP		0.68
MPC		0.11
ClinPred		0.39	T
GERP RS		3.3
Varity_R		0.031
gMVP		0.16
Mutation Taster		=95/5	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: rs1553131489; hg19: chr1-45800129;