rs747821285

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PP3_StrongPP5

The NM_001199107.2(TBC1D24):​c.328G>A​(p.Gly110Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000548 in 1,458,606 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. G110G) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TBC1D24
NM_001199107.2 missense

Scores

6
5
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 6.48

Publications

5 publications found
Variant links:
Genes affected
TBC1D24 (HGNC:29203): (TBC1 domain family member 24) This gene encodes a protein with a conserved domain, referred to as the TBC domain, characteristic of proteins which interact with GTPases. TBC domain proteins may serve as GTPase-activating proteins for a particular group of GTPases, the Rab (Ras-related proteins in brain) small GTPases which are involved in the regulation of membrane trafficking. Mutations in this gene are associated with familial infantile myoclonic epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2011]
TBC1D24 Gene-Disease associations (from GenCC):
  • DOORS syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet, PanelApp Australia, G2P
  • familial infantile myoclonic epilepsy
    Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet
  • autosomal dominant nonsyndromic hearing loss 65
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nonsyndromic hearing loss
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • malignant migrating partial seizures of infancy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • focal epilepsy-intellectual disability-cerebro-cerebellar malformation
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hearing loss, autosomal recessive
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • progressive myoclonic epilepsy with dystonia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • nonsyndromic genetic hearing loss
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • autosomal recessive nonsyndromic hearing loss 86
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_001199107.2
PP3
MetaRNN computational evidence supports a deleterious effect, 0.967
PP5
Variant 16-2496476-G-A is Pathogenic according to our data. Variant chr16-2496476-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 183154.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TBC1D24NM_001199107.2 linkc.328G>A p.Gly110Ser missense_variant Exon 2 of 8 ENST00000646147.1 NP_001186036.1 Q9ULP9-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TBC1D24ENST00000646147.1 linkc.328G>A p.Gly110Ser missense_variant Exon 2 of 8 NM_001199107.2 ENSP00000494678.1 Q9ULP9-1
ENSG00000260272ENST00000564543.1 linkc.328G>A p.Gly110Ser missense_variant Exon 1 of 3 2 ENSP00000455547.1 H3BQ06

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000407
AC:
1
AN:
245840
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000548
AC:
8
AN:
1458606
Hom.:
0
Cov.:
31
AF XY:
0.00000551
AC XY:
4
AN XY:
725776
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.0000224
AC:
1
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86234
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50378
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111874
Other (OTH)
AF:
0.00
AC:
0
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.0000423
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000826
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:3Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

DOORS syndrome Pathogenic:2
Jan 01, 2014
Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

We identified 26 families with DOORS syndrome; each patient had at least 3 of the 5 well-described features of DOORS syndrome, which include deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. A combination of whole-exome sequencing and Sanger sequencing identified homozygous or compound heterozygous pathogenic variants in TBC1D24 in 11 individuals from 9 families. -

Dec 22, 2014
Division of Medical Genetics; Sainte-Justine Hospital
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Pathogenic:1
Oct 23, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28428906, 28606688, 24291220) -

Developmental and epileptic encephalopathy, 1;C3892048:Autosomal dominant nonsyndromic hearing loss 65;CN236805:Caused by mutation in the TBC1 domain family, member 24 Uncertain:1
Aug 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 110 of the TBC1D24 protein (p.Gly110Ser). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with DOORS syndrome (Deafness, Onychodystrophy, Osteodystrophy, mental Retardation, and Seizures) (PMID: 24291220; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 183154). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt TBC1D24 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.83
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.47
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Benign
0.18
.;T;T;.;.;.;.
Eigen
Uncertain
0.57
Eigen_PC
Uncertain
0.52
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.87
.;.;D;D;D;D;D
M_CAP
Pathogenic
0.80
D
MetaRNN
Pathogenic
0.97
D;D;D;D;D;D;D
MetaSVM
Benign
-1.2
T
MutationAssessor
Benign
1.5
L;L;L;.;.;L;.
PhyloP100
6.5
PrimateAI
Uncertain
0.56
T
PROVEAN
Pathogenic
-4.6
D;.;D;.;.;.;D
REVEL
Pathogenic
0.74
Sift
Benign
0.033
D;.;D;.;.;.;D
Sift4G
Benign
0.095
T;.;T;.;.;T;T
Polyphen
1.0
D;D;D;.;.;D;.
Vest4
0.15
MutPred
0.81
Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);Loss of methylation at R109 (P = 0.0455);
MVP
0.80
MPC
1.0, 1.3
ClinPred
0.96
D
GERP RS
5.6
PromoterAI
0.068
Neutral
Varity_R
0.40
gMVP
0.82
Mutation Taster
=74/26
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs747821285; hg19: chr16-2546477; COSMIC: COSV99565226; COSMIC: COSV99565226; API