Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PS1_Very_StrongPM1PM2PP2PP3_Moderate
The NM_001904.4(CTNNB1):c.1723G>C(p.Gly575Arg) 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. 12/21 in silico tools predict a damaging outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin ClinVar.
CTNNB1 (HGNC:2514): (catenin beta 1) The protein encoded by this gene is part of a complex of proteins that constitute adherens junctions (AJs). AJs are necessary for the creation and maintenance of epithelial cell layers by regulating cell growth and adhesion between cells. The encoded protein also anchors the actin cytoskeleton and may be responsible for transmitting the contact inhibition signal that causes cells to stop dividing once the epithelial sheet is complete. Finally, this protein binds to the product of the APC gene, which is mutated in adenomatous polyposis of the colon. Mutations in this gene are a cause of colorectal cancer (CRC), pilomatrixoma (PTR), medulloblastoma (MDB), and ovarian cancer. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2016]
Verdict is Pathogenic. Variant got 15 ACMG points.
PS1
?
PS1 - Same amino acid change as a previously established pathogenic variant regardless of nucleotide change
Transcript NM_001904.4 (CTNNB1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 208674
PM1
?
PM1 - Located in a mutational hot spot and/or critical and well-established functional domain (e.g., active site of an enzyme) without benign variation
In a helix (size 14) in uniprot entity CTNB1_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_001904.4
PM2
?
PM2 - Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium
Very rare variant in population databases, with high coverage;
PP2
?
PP2 - Missense variant in a gene that has a low rate of benign missense variation and in which missense variants are a common mechanism of disease
Missense variant where missense usually causes diseases, CTNNB1
PP3
?
PP3 - Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc.)
MetaRNN computational evidence supports a deleterious effect, 0.875