rs879254257

chr1-45332209-C-Achr1-45332209-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_001048174.2(MUTYH):c.806G>T(p.Cys269Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C269Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 7.55

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_001048174.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.890G>T	p.Cys297Phe	missense_variant	10/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.806G>T	p.Cys269Phe	missense_variant	10/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.890G>T	p.Cys297Phe	missense_variant	10/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.806G>T	p.Cys269Phe	missense_variant	10/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Carcinoma of colon Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The p.Cys297Phe variant has not been reported in the literature nor previously identified by our laboratory. The Cys residue is conserved across mammals and computational analyses (PolyPhen2, SIFT, AlignGVGD) suggest that the Phe variant may impact the protein. However, this information is not predictive enough to assume pathogenicity. The presence of this variant in combination with a reported pathogenic variant increases the likelihood that the p.Cys297Phe variant is pathogenic. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more pathogenic role for this variant. This variant is classified as a Predicted Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	26
Dann	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-10	D;D;D;D;D;D;D;D;D;.;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;.;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	.;.;.;.;.;D;D;.;D;.;.;.
Vest4		0.98
MutPred		0.87		.;.;.;.;.;.;.;.;Loss of disorder (P = 0.1063);.;.;.;
MVP		1.0
MPC		0.68
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.97
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs879254257; hg19: chr1-45797881;