rs1484876251

chr1-45329370-AG-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001048174.2(MUTYH):c.1501del(p.Leu501TrpfsTer42) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,212 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. L501L) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: MUTYH NM_001048174.2 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.64

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.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0415 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MUTYH	NM_001128425.2	c.1585del	p.Leu529TrpfsTer42	frameshift_variant	16/16	ENST00000710952.2
MUTYH	NM_001048174.2	c.1501del	p.Leu501TrpfsTer42	frameshift_variant	16/16	ENST00000456914.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MUTYH	ENST00000710952.2	c.1585del	p.Leu529TrpfsTer42	frameshift_variant	16/16		NM_001128425.2
MUTYH	ENST00000456914.7	c.1501del	p.Leu501TrpfsTer42	frameshift_variant	16/16	1	NM_001048174.2	A1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152212 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000241

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.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152212 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74370

Gnomad4 AFR AF: 0.0000241

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: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 19, 2017

The c.1585delC variant, located in coding exon 16 of the MUTYH gene, results from a deletion of one nucleotide at nucleotide position 1585, causing a translational frameshift with a predicted alternate stop codon (p.L529Wfs*42). Frameshifts are typically deleterious in nature, however, this frameshift occurs at the 3' terminus of MUTYH, is not expected to trigger nonsense-mediated mRNA decay, and impacts only the last 20 amino acids of the protein in addition to elongating the protein by 21 amino acids. The exact functional impact of these altered amino acids is unknown at this time. However, structural analysis suggests that this alteration is expected to result in loss of predicted and confirmed interaction and regulatory domains, including PCNA-binding Pip domain, which results in loss of DNA repair function in-vitro (Chang DY et al. J. Biol. Chem. 2002 Apr;277(14):11853-8), as well as gain of putative interaction motifs, including a nuclear-hormone-receptor coactivator motif (NRBOX) (Leo C et al. Gene 2000 Mar;245(1):1-11). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

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: rs1484876251; hg19: chr1-45795042;