1-45331452-G-A

Variant names:

• chr1-45331452-G-A
• rs1280648051
• NM_001128425.2:c.1291C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001128425.2(MUTYH):​c.1291C>T​(p.Leu431Phe) 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 1,461,880 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L431V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MUTYH NM_001128425.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.209
• 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 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 20 benign, 54 uncertain in NM_001128425.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2509783).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001128425.2. 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.1291C>T	p.Leu431Phe	missense	Exon 13 of 16	NP_001121897.1
	MUTYH	NM_001048174.2	MANE Select	c.1207C>T	p.Leu403Phe	missense	Exon 13 of 16	NP_001041639.1
	MUTYH	NM_012222.3		c.1282C>T	p.Leu428Phe	missense	Exon 13 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.1291C>T	p.Leu431Phe	missense	Exon 13 of 16	ENSP00000518552.2
	MUTYH	ENST00000456914.7	TSL:1 MANE Select	c.1207C>T	p.Leu403Phe	missense	Exon 13 of 16	ENSP00000407590.2
	MUTYH	ENST00000372098.7	TSL:1	c.1282C>T	p.Leu428Phe	missense	Exon 13 of 16	ENSP00000361170.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727240

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: 53406

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

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

Jul 25, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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 leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 431 of the MUTYH protein (p.Leu431Phe).

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 27, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L431F variant (also known as c.1291C>T), located in coding exon 13 of the MUTYH gene, results from a C to T substitution at nucleotide position 1291. The leucine at codon 431 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	0.0017	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.38	T
Eigen	Benign	-0.22
Eigen_PC	Benign	-0.11
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.057	D
MetaRNN	Benign	0.25	T
MetaSVM	Benign	-0.31	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		0.21
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-1.8	N
REVEL	Benign	0.13
Sift	Uncertain	0.013	D
Sift4G	Uncertain	0.043	D
Polyphen		0.020	B
Vest4		0.40
MutPred		0.41		Loss of helix (P = 0.2022)
MVP		0.78
MPC		0.13
ClinPred		0.75	D
GERP RS		3.4
Varity_R		0.23
gMVP		0.45
Mutation Taster		=44/56	disease causing

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: rs1280648051; hg19: chr1-45797124;