Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PM2
The NM_003106.4(SOX2):c.540C>A(p.Tyr180*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. Y180Y) has been classified as Likely benign.
SOX2 (HGNC:11195): (SRY-box transcription factor 2) This intronless gene encodes a member of the SRY-related HMG-box (SOX) family of transcription factors involved in the regulation of embryonic development and in the determination of cell fate. The product of this gene is required for stem-cell maintenance in the central nervous system, and also regulates gene expression in the stomach. Mutations in this gene have been associated with optic nerve hypoplasia and with syndromic microphthalmia, a severe form of structural eye malformation. This gene lies within an intron of another gene called SOX2 overlapping transcript (SOX2OT). [provided by RefSeq, Jul 2008]
SOX2-OT (HGNC:20209): (SOX2 overlapping transcript) This gene produces alternatively spliced long non-coding RNAs. These RNAs were observed to be upregulated in tumor cells and positively correlated to expression of the SRY-box 2 gene. Overexpression of these transcripts may promote cell proliferation. [provided by RefSeq, Dec 2017]
Our verdict: Pathogenic. The variant received 10 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. There are 26 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;