chr22-31906252-C-T

Position:

• chr22-31906252-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_001242896.3(DEPDC5):​c.4567C>T​(p.Gln1523Ter) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DEPDC5 NM_001242896.3 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1 O:1
• Conservation: PhyloP100: 5.74

Genes affected

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 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 0.0509 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-31906252-C-T is Pathogenic according to our data. Variant chr22-31906252-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 183030.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, not_provided=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DEPDC5	NM_001242896.3	c.4567C>T	p.Gln1523Ter	stop_gained	43/43	ENST00000651528.2	NP_001229825.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DEPDC5	ENST00000651528.2	c.4567C>T	p.Gln1523Ter	stop_gained	43/43		NM_001242896.3	ENSP00000498382	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial focal epilepsy with variable foci Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 23, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the DEPDC5 protein in which other variant(s) (p.Asp1565*) have been determined to be pathogenic (PMID: 28549235, 31639411). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. Experimental studies have shown that this premature translational stop signal affects DEPDC5 function (PMID: 25366275). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. ClinVar contains an entry for this variant (Variation ID: 183030). This premature translational stop signal has been observed in individual(s) with nocturnal frontal lobe epilepsy (PMID: 23542701). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln1523*) in the DEPDC5 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 81 amino acid(s) of the DEPDC5 protein. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 23, 2023

Not expected to trigger nonsense-mediated mRNA decay Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Epilepsy, familial focal, with variable foci 1 Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.26	T
MetaRNN	Benign	0.36	T
MetaSVM	Benign	-0.90	T
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
ClinPred		1.0	D
GERP RS		4.0

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: rs797044546; hg19: chr22-32302238;