rs1249590916

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP3

The NM_001199107.2(TBC1D24):​c.1475C>T​(p.Ser492Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000437 in 1,601,104 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S492T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

TBC1D24
NM_001199107.2 missense

Scores

8
8
3

Clinical Significance

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

Conservation

PhyloP100: 5.73

Publications

0 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: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 14 uncertain in NM_001199107.2
PP3
MetaRNN computational evidence supports a deleterious effect, 0.817

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TBC1D24NM_001199107.2 linkc.1475C>T p.Ser492Phe missense_variant Exon 7 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.1475C>T p.Ser492Phe missense_variant Exon 7 of 8 NM_001199107.2 ENSP00000494678.1 Q9ULP9-1
ENSG00000260272ENST00000564543.1 linkc.965+3327C>T intron_variant Intron 1 of 2 2 ENSP00000455547.1 H3BQ06

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152238
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
218130
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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:
0.00000276
AC:
4
AN:
1448866
Hom.:
0
Cov.:
33
AF XY:
0.00000417
AC XY:
3
AN XY:
719628
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33220
American (AMR)
AF:
0.00
AC:
0
AN:
43378
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25814
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39064
South Asian (SAS)
AF:
0.00
AC:
0
AN:
83904
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51336
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5708
European-Non Finnish (NFE)
AF:
0.00000361
AC:
4
AN:
1106580
Other (OTH)
AF:
0.00
AC:
0
AN:
59862
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.0000197
AC:
3
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74372
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41464
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Mar 20, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Ser492Phe variant in TBC1D24 has been previously reported by our laborator y in one individual with hearing loss. Data from large population studies are in sufficient to assess the frequency of this variant in the general population. C omputational prediction tools and conservation analyses do not provide strong su pport for or against an impact to the protein. In summary, the clinical signific ance of the p.Ser492Phe variant is uncertain. -

Inborn genetic diseases Uncertain:1
Apr 22, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1475C>T (p.S492F) alteration is located in exon 7 (coding exon 6) of the TBC1D24 gene. This alteration results from a C to T substitution at nucleotide position 1475, causing the serine (S) at amino acid position 492 to be replaced by a phenylalanine (F). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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
Jan 25, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 492 of the TBC1D24 protein (p.Ser492Phe). This variant is not present in population databases (gnomAD no frequency). 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: 505527). 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 expected to disrupt TBC1D24 protein function with a positive 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
Uncertain
0.55
BayesDel_addAF
Pathogenic
0.29
D
BayesDel_noAF
Pathogenic
0.18
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Benign
0.17
.;T;T;.
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
.;.;D;D
M_CAP
Uncertain
0.094
D
MetaRNN
Pathogenic
0.82
D;D;D;D
MetaSVM
Uncertain
-0.16
T
MutationAssessor
Pathogenic
3.5
.;H;H;.
PhyloP100
5.7
PrimateAI
Uncertain
0.66
T
PROVEAN
Benign
-2.2
N;.;N;.
REVEL
Uncertain
0.44
Sift
Uncertain
0.0020
D;.;D;.
Sift4G
Uncertain
0.0060
D;.;D;D
Polyphen
1.0
D;D;D;D
Vest4
0.90
MutPred
0.65
.;Loss of sheet (P = 0.0104);Loss of sheet (P = 0.0104);.;
MVP
0.86
MPC
1.1
ClinPred
0.99
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.67
gMVP
0.67
Mutation Taster
=39/61
disease causing

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: rs1249590916; hg19: chr16-2550441; API