1-45329316-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001048174.2(MUTYH):c.1556C>T(p.Ala519Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 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. A519E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -1.05

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0755907).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.1640C>T	p.Ala547Val	missense_variant	16/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.1556C>T	p.Ala519Val	missense_variant	16/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.1640C>T	p.Ala547Val	missense_variant	16/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.1556C>T	p.Ala519Val	missense_variant	16/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000205 AC: 3 AN: 1461870 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial adenomatous polyposis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 03, 2023

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 547 of the MUTYH protein (p.Ala547Val). 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: 481812). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 09, 2016

The p.A547V variant (also known as c.1640C>T), located in coding exon 16 of the MUTYH gene, results from a C to T substitution at nucleotide position 1640. The alanine at codon 547 is replaced by valine, an amino acid with similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.001% (greater than 200000 alleles tested) in our clinical cohort. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.095	T
BayesDel_noAF	Benign	-0.37
Cadd	Benign	1.0
Dann	Benign	0.97
Eigen	Benign	-0.81
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.029	N
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.076	T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.99	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N;N;N;N;N;N;N;N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.58	N;N;N;N;N;N;N;N;N;N;N;.
REVEL	Benign	0.11
Sift	Uncertain	0.015	D;T;D;T;T;T;D;T;T;D;D;.
Sift4G	Benign	0.12	T;T;T;T;T;T;T;T;T;T;T;T
Polyphen		0.31, 0.43	.;.;.;.;.;.;B;B;.;.;B;.
Vest4		0.067
MutPred		0.086		.;.;.;.;.;.;.;.;.;.;Loss of relative solvent accessibility (P = 0.0676);.;
MVP		0.70
MPC		0.11
ClinPred		0.040	T
GERP RS		-0.94
Varity_R		0.079
gMVP		0.29

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553122784; hg19: chr1-45794988;