1-45332594-C-T

Position:

• chr1-45332594-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_001048174.2(MUTYH):​c.586G>A​(p.Ala196Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,854 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A196D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MUTYH NM_001048174.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 5.79

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 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 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, 0.748

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.670G>A	p.Ala224Thr	missense_variant	8/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.586G>A	p.Ala196Thr	missense_variant	8/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.670G>A	p.Ala224Thr	missense_variant	8/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.586G>A	p.Ala196Thr	missense_variant	8/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461854 Hom.: 0 Cov.: 36 AF XY: 0.00000550 AC XY: 4 AN XY: 727236

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: 0.00000629

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 25, 2021	The p.A224T variant (also known as c.670G>A), located in coding exon 8 of the MUTYH gene, results from a G to A substitution at nucleotide position 670. The alanine at codon 224 is replaced by threonine, an amino acid with similar properties. In a study of whole-exome sequencing in patients with features of Cowden syndrome (CS) or Bannayan-Riley-Ruvalcaba syndrome (BRRS) and negative PTEN testing, this alteration was identified in 0/87 patients with CS or BRRS and 1/3476 patients from The Cancer Genome Atlas (TCGA) (Yehia L et al. PLoS Genet, 2018 04;14:e1007352). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 30, 2019	- -

Familial adenomatous polyposis 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 01, 2016

Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a MUTYH-related disease. In summary, this is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. This sequence change replaces alanine with threonine at codon 224 of the MUTYH protein (p.Ala224Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.040
CADD	Uncertain	25
DANN	Pathogenic	1.0
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.75	D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.93	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-3.4	D;D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0040	D;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		0.99, 0.99, 0.99	.;.;.;.;.;D;D;.;D;.;.;.
Vest4		0.72
MutPred		0.56		.;.;.;.;.;.;.;.;Loss of phosphorylation at T219 (P = 0.1657);.;.;.;
MVP		0.98
MPC		0.54
ClinPred		0.98	D
GERP RS		5.4
Varity_R		0.80
gMVP		0.55

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: rs878854192; hg19: chr1-45798266; COSMIC: COSV58343910; COSMIC: COSV58343910;