chr1-45331184-T-A

Position:

• chr1-45331184-T-A

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1 PM2 PP3 PP5_Very_Strong

The NM_001048174.2(MUTYH):​c.1390A>T​(p.Lys464Ter) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,200 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 33)
• Consequence: MUTYH NM_001048174.2 stop_gained, splice_region
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.41

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 Pathogenic. Variant got 19 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 1-45331184-T-A is Pathogenic according to our data. Variant chr1-45331184-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 216081.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.1474A>T	p.Lys492Ter	stop_gained, splice_region_variant	14/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.1390A>T	p.Lys464Ter	stop_gained, splice_region_variant	14/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.1474A>T	p.Lys492Ter	stop_gained, splice_region_variant	14/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.1390A>T	p.Lys464Ter	stop_gained, splice_region_variant	14/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152200 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152200 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74344

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Sep 08, 2023	The p.K492* variant (also known as c.1474A>T), located in coding exon 14 of the MUTYH gene, results from an A to T substitution at nucleotide position 1474. This changes the amino acid from a lysine to a stop codon within coding exon 14. This stop codon occurs at the 3' terminus of MUTYH, is not expected to trigger nonsense-mediated mRNA decay, and removes only the last 58 amino acids of the protein. However, premature stop codons are typically deleterious in nature and a significant portion of the protein is affected (Ambry internal data). Based on internal structural analysis, p.K492* results in loss of the PCNA-binding motif (Chang DY et al. J. Biol. Chem. 2002 Apr;277:11853-8). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 15, 2020	This variant is located in the MUTYH protein. Splice site prediction tools suggest that this variant may not impact RNA splicing. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of MUTYH function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Familial adenomatous polyposis 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

May 11, 2022

This sequence change creates a premature translational stop signal (p.Lys492*) in the MUTYH gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MUTYH are known to be pathogenic (PMID: 18534194, 20663686). 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: 216081). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
Vest4		0.84
ClinPred		1.0	D
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.77		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.77		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs863224502; hg19: chr1-45796856;