Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate
The NM_001242896.3(DEPDC5):c.871+1G>T variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).
DEPDC5 (HGNC:18423): (DEP domain containing 5, GATOR1 subcomplex subunit) This gene encodes a member of the IML1 family of proteins involved in G-protein signaling pathways. The mechanistic target of rapamycin complex 1 (mTORC1) pathway regulates cell growth by sensing the availability of nutrients. The protein encoded by this gene is a component of the GATOR1 (GAP activity toward Rags) complex which inhibits the amino acid-sensing branch of the mTORC1 pathway. Mutations in this gene are associated with autosomal dominant familial focal epilepsy with variable foci. A single nucleotide polymorphism in an intron of this gene has been associated with an increased risk of hepatocellular carcinoma in individuals with chronic hepatitis C virus infection. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2014]
Verdict is Pathogenic. Variant got 12 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.8, offset of 23, new splice context is: atgGTgcgg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 22-31797704-G-T is Pathogenic according to our data. Variant chr22-31797704-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 466497.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr22-31797704-G-T is described in Lovd as [Likely_pathogenic].
Familial focal epilepsy with variable foci Pathogenic:1
May 14, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
In summary, donor and acceptor splice site variants are typically loss-of-function (PMID: 16199547), and loss-of-function variants in DEPDC5 are known to be pathogenic (PMID: 26505888). However, without additional functional and/or genetic data, this variant has been classified as Likely Pathogenic. This sequence change affects a donor splice site in intron 13 of the DEPDC5 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. This variant has not been reported in the literature in individuals with a DEPDC5-related disease. -