1-45331316-G-C

Variant names:

• chr1-45331316-G-C
• rs786202133
• NM_001128425.2:c.1342C>G

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PS3 PM1 PM2 PP3_Strong PP5

The NM_001048174.2(MUTYH):​c.1258C>G​(p.His420Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,890 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 Conflicting classifications of pathogenicity (no stars). ClinVar reports functional evidence for this variant: "SCV000215473: In a massively parallel cell-based functional assay testing 7,8-dihydro-8-oxoguanine:adenine (8OG:A) repair activity, a byproduct of oxidative damage, this variant was reported to be non-functional (Hemker SL et al. Am J Hum Genet. Published online July 29, 2025. DOI: 10.1016/j.ajhg.2025.07.005). A different functional analyses of this alteration showed decreased/impaired DNA glycosylase activity compared to wild type MUTYH (Forsbring M, Carcinogenesis 2009 Jul" and additional evidence is available in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H420N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 9.21
• Publications: 9 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: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, G2P, Orphanet
• 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: AR, AD Classification: NO_KNOWN Submitted by: ClinGen

ENSG00000288208 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV000215473: In a massively parallel cell-based functional assay testing 7,8-dihydro-8-oxoguanine:adenine (8OG:A) repair activity, a byproduct of oxidative damage, this variant was reported to be non-functional (Hemker SL et al. Am J Hum Genet. Published online July 29, 2025. DOI: 10.1016/j.ajhg.2025.07.005). A different functional analyses of this alteration showed decreased/impaired DNA glycosylase activity compared to wild type MUTYH (Forsbring M, Carcinogenesis 2009 Jul; 30(7):1147-54).
• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 36 uncertain in NM_001048174.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.954
• PP5: Variant 1-45331316-G-C is Pathogenic according to our data. Variant chr1-45331316-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 185383.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MUTYH	NM_001128425.2	MANE Plus Clinical	c.1342C>G	p.His448Asp	missense	Exon 14 of 16	NP_001121897.1	E5KP25
	MUTYH	NM_001048174.2	MANE Select	c.1258C>G	p.His420Asp	missense	Exon 14 of 16	NP_001041639.1	Q9UIF7-6
	MUTYH	NM_012222.3		c.1333C>G	p.His445Asp	missense	Exon 14 of 16	NP_036354.1	Q9UIF7-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MUTYH	ENST00000710952.2	MANE Plus Clinical	c.1342C>G	p.His448Asp	missense	Exon 14 of 16	ENSP00000518552.2	E5KP25
	MUTYH	ENST00000456914.7	TSL:1 MANE Select	c.1258C>G	p.His420Asp	missense	Exon 14 of 16	ENSP00000407590.2	Q9UIF7-6
	MUTYH	ENST00000372098.7	TSL:1	c.1333C>G	p.His445Asp	missense	Exon 14 of 16	ENSP00000361170.3	Q9UIF7-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

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: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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: 60394

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
1	2	-	Familial adenomatous polyposis 2 (3)
1	-	-	Hereditary cancer-predisposing syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		9.2
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-8.3	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.99	D
Vest4		0.93
MutPred		0.78		Gain of catalytic residue at H448 (P = 0.0466)
MVP		1.0
MPC		0.64
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.98
gMVP		0.88
Mutation Taster		=1/99	disease causing (ClinVar)

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: rs786202133; hg19: chr1-45796988; COSMIC: COSV58344509; COSMIC: COSV58344509;