NM_001199107.2:c.920A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM5BP4

The NM_001199107.2(TBC1D24):c.920A>G(p.Asn307Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000515 in 1,610,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N307D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000056 ( 0 hom. )

Consequence

TBC1D24
NM_001199107.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 9.26

Publications

3 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

TBC1D24 links:

ENSG00000260272 (HGNC:):

ENSG00000260272 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr16-2497067-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 425556.Status of the report is criteria_provided_single_submitter, 1 stars.

BP4

Computational evidence support a benign effect (MetaRNN=0.33535725).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D24	NM_001199107.2 link	c.920A>G	p.Asn307Ser	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
TBC1D24	ENST00000646147.1 link	c.920A>G	p.Asn307Ser	missense_variant	Exon 2 of 8		NM_001199107.2	ENSP00000494678.1		Q9ULP9-1
ENSG00000260272	ENST00000564543.1 link	c.920A>G	p.Asn307Ser	missense_variant	Exon 1 of 3	2		ENSP00000455547.1		H3BQ06

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152204

Hom.:

Cov.:

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:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000408

AC:

AN:

244950

AF XY:

0.00000750

show subpopulations

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:

0.00000897

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000555

AC:

AN:

1458744

Hom.:

Cov.:

AF XY:

0.0000606

AC XY:

AN XY:

725794

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000199

AC:

AN:

50312

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000701

AC:

AN:

1111998

Other (OTH)

AF:

0.0000331

AC:

AN:

60374

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.460

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74358

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41448

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.0000941

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000364

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000826

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

TBC1D24-related disorder

Pathogenic:1

Jul 19, 2023

PreventionGenetics, part of Exact Sciences

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The TBC1D24 c.920A>G variant is predicted to result in the amino acid substitution p.Asn307Ser. This variant was reported to be significantly enriched in individuals with age-related hearing loss in large GWAS studies. A more recent GWAS study showed the odds ratio was more than 4, suggesting a strong association (described as rs761934676, OR=6.59, p=5.9×10-13 in Ivarsdottir et al. 2021. PubMed ID: 34108613; OR=4.14, p=5.10E−09 in Praveen et al. 2022. PubMed ID: 35661827). This variant is reported in 0.00090% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-2547069-A-G). Two different missense substitutions affecting the same amino acid have been reported: p.Asn307His segregated in two large families with autosomal dominant non-syndromic hearing loss (Parzefall et al 2020. PubMed ID: 33281559) and p.Asn307Asp was compound heterozygous in two siblings with TBC1D24-related epilepsy (Appavu et al 2016. PubMed ID: 27502353). Taken together, we interpret this variant as likely pathogenic. -

not specified

Uncertain:1

Mar 11, 2020

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Asn307Ser variant in TBC1D24 has not been previously reported in individuals with hearing loss but has been identified in 1/111448 European chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant has also been reported in ClinVar (Variation ID 583333). Computational prediction tools and conservation analysis suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2, PP3. -

Dysarthria;C0027066:Myoclonus;C0028738:Nystagmus;C0036572:Seizure;C0040822:Tremor

Uncertain:1

Oct 09, 2019

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Jun 30, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. 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. ClinVar contains an entry for this variant (Variation ID: 583333). This variant has not been reported in the literature in individuals affected with TBC1D24-related conditions. This variant is present in population databases (rs761934676, gnomAD 0.0009%). This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 307 of the TBC1D24 protein (p.Asn307Ser). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.57

BayesDel_addAF

Benign

-0.15

BayesDel_noAF

Benign

-0.45

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.051

.;T;T;.;.;.;.

Eigen

Pathogenic

0.72

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Uncertain

0.97

LIST_S2

Pathogenic

0.99

.;.;D;D;D;D;D

M_CAP

Benign

0.037

MetaRNN

Benign

0.34

T;T;T;T;T;T;T

MetaSVM

Benign

-0.87

MutationAssessor

Uncertain

2.7

M;M;M;.;.;M;.

PhyloP100

9.3

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-1.6

N;.;N;.;.;.;N

REVEL

Benign

0.16

Sift

Benign

0.061

T;.;D;.;.;.;T

Sift4G

Pathogenic

0.0

D;.;D;.;.;D;D

Polyphen

1.0

D;D;D;.;.;D;.

Vest4

0.76

MVP

0.82

MPC

0.98, 1.3

ClinPred

0.89

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.19

gMVP

0.76

Mutation Taster

=84/16

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over