16-2496924-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM1BP4_Moderate

The NM_001199107.2(TBC1D24):​c.776C>T​(p.Pro259Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000192 in 1,613,928 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

TBC1D24
NM_001199107.2 missense

Scores

1
2
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 4.36
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM1
In a domain Rab-GAP TBC (size 215) in uniprot entity TBC24_HUMAN there are 17 pathogenic changes around while only 3 benign (85%) in NM_001199107.2
BP4
Computational evidence support a benign effect (MetaRNN=0.11510453).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TBC1D24NM_001199107.2 linkc.776C>T p.Pro259Leu 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.776C>T p.Pro259Leu missense_variant Exon 2 of 8 NM_001199107.2 ENSP00000494678.1 Q9ULP9-1
ENSG00000260272ENST00000564543.1 linkc.776C>T p.Pro259Leu missense_variant Exon 1 of 3 2 ENSP00000455547.1 H3BQ06

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152228
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000441
AC:
11
AN:
249438
Hom.:
0
AF XY:
0.0000739
AC XY:
10
AN XY:
135374
show subpopulations
Gnomad AFR exome
AF:
0.0000646
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000261
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000884
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461700
Hom.:
0
Cov.:
31
AF XY:
0.0000234
AC XY:
17
AN XY:
727178
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000162
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000899
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152228
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74364
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000414
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000756
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Aug 21, 2023
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.776C>T (p.P259L) alteration is located in exon 2 (coding exon 1) of the TBC1D24 gene. This alteration results from a C to T substitution at nucleotide position 776, causing the proline (P) at amino acid position 259 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Jul 18, 2017
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The P259L variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The P259L variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). This variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. However, this substitution occurs at a position that is not conserved, and in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. -

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
Apr 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 259 of the TBC1D24 protein (p.Pro259Leu). This variant is present in population databases (rs779398267, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with TBC1D24-related conditions. ClinVar contains an entry for this variant (Variation ID: 450477). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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
Benign
0.071
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.48
CADD
Benign
19
DANN
Uncertain
0.98
DEOGEN2
Benign
0.017
.;T;T;.;.;.;.
Eigen
Benign
-0.16
Eigen_PC
Benign
-0.088
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Benign
0.85
.;.;T;T;T;T;T
M_CAP
Benign
0.046
D
MetaRNN
Benign
0.12
T;T;T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.4
L;L;L;.;.;L;.
PrimateAI
Uncertain
0.50
T
PROVEAN
Benign
-2.1
N;.;N;.;.;.;N
REVEL
Benign
0.048
Sift
Benign
0.24
T;.;T;.;.;.;T
Sift4G
Benign
0.28
T;.;T;.;.;T;T
Polyphen
0.60
P;P;P;.;.;P;.
Vest4
0.20
MutPred
0.44
Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);Gain of stability (P = 0.0106);
MVP
0.69
MPC
0.34, 0.58
ClinPred
0.15
T
GERP RS
4.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.067
gMVP
0.23

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs779398267; hg19: chr16-2546925; API