chr1-45332600-C-T

Position:

• chr1-45332600-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001048174.2(MUTYH):​c.580G>A​(p.Ala194Thr) 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 (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.56

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.928

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MUTYH	NM_001128425.2	c.664G>A	p.Ala222Thr	missense_variant	8/16	ENST00000710952.2	NP_001121897.1
MUTYH	NM_001048174.2	c.580G>A	p.Ala194Thr	missense_variant	8/16	ENST00000456914.7	NP_001041639.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MUTYH	ENST00000710952.2	c.664G>A	p.Ala222Thr	missense_variant	8/16		NM_001128425.2	ENSP00000518552
MUTYH	ENST00000456914.7	c.580G>A	p.Ala194Thr	missense_variant	8/16	1	NM_001048174.2	ENSP00000407590	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

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

Labcorp Genetics (formerly Invitae), Labcorp

Sep 20, 2017

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with MUTYH-related disease. ClinVar contains an entry for this variant (Variation ID: 428280). This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with threonine at codon 222 of the MUTYH protein (p.Ala222Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 10, 2013

​The p.A222T variant (also known as c.664G>A) is located in exon 8 of the MUTYH gene. This alteration results from a G to A substitution at nucleotide position 664. The alanine at codon 222 is replaced by threonine, 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. To date, this alteration has been detected with an allele frequency of approximately 0.02% (greater than 5500 alleles tested) in our clinical cohort (includes this individual). Based on protein sequence alignment, this amino acid position is completely conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.46
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.62	.;.;.;.;.;D;.;.;.;T;.;T
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	.;D;.;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	.;.;.;.;.;H;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.7	D;D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	.;.;.;.;.;D;D;.;D;.;.;.
Vest4		0.89
MutPred		0.76		.;.;.;.;.;.;.;.;Loss of phosphorylation at T219 (P = 0.1003);.;.;.;
MVP		0.99
MPC		0.54
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.96
gMVP		0.72

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1114167683; hg19: chr1-45798272;