Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6
The NM_001048174.2(MUTYH):c.305-6C>T variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000164 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
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]
Verdict is Likely_benign. Variant got -3 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.52).
BP6
Variant 1-45333176-G-A is Benign according to our data. Variant chr1-45333176-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 383957.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=4}. Variant chr1-45333176-G-A is described in Lovd as [Likely_benign].
Likely benign, criteria provided, single submitter
clinical testing
GeneDx
Oct 14, 2019
- -
Uncertain significance, criteria provided, single submitter
clinical testing
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Nov 03, 2021
- -
Uncertain significance, criteria provided, single submitter
clinical testing
Quest Diagnostics Nichols Institute San Juan Capistrano
Jan 10, 2020
- -
not specified Uncertain:2
Uncertain significance, criteria provided, single submitter
clinical testing
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Aug 15, 2023
- -
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Sep 28, 2018
Variant summary: MUTYH c.389-6C>T alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 3.7e-05 in 246170 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.389-6C>T in individuals affected with MUTYH-associated Polyposis and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as likely benign, and one laboratory classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Familial adenomatous polyposis 2 Benign:1
Likely benign, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jan 17, 2024
- -
Hereditary cancer-predisposing syndrome Benign:1
Likely benign, criteria provided, single submitter