X-106802972-G-T

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_017752.3(TBC1D8B):​c.119G>T​(p.Gly40Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000034 in 1,204,856 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 12 hemizygotes in GnomAD. In-silico tool predicts a benign 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. G40E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000045 ( 0 hom., 0 hem., cov: 23)
Exomes 𝑓: 0.000033 ( 0 hom. 12 hem. )

Consequence

TBC1D8B
NM_017752.3 missense

Scores

9
8

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.05

Publications

0 publications found
Variant links:
Genes affected
TBC1D8B (HGNC:24715): (TBC1 domain family member 8B) This gene encodes a protein with a TBC (Tre-2/Bub2/CDC16) domain. Some mammalian proteins with this domain have been shown to function as Rab-GAPs by binding to specific Rab proteins and affecting their GTPase activity. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2011]
TBC1D8B Gene-Disease associations (from GenCC):
  • nephrotic syndrome, type 20
    Inheritance: XL Classification: STRONG, MODERATE, LIMITED Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • familial idiopathic steroid-resistant nephrotic syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21612483).
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.0000447 (5/111962) while in subpopulation AMR AF = 0.000471 (5/10619). AF 95% confidence interval is 0.000185. There are 0 homozygotes in GnomAd4. There are 0 alleles in the male GnomAd4 subpopulation. Median coverage is 23. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAd4 at 5 XL,AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TBC1D8BNM_017752.3 linkc.119G>T p.Gly40Val missense_variant Exon 1 of 21 ENST00000357242.10 NP_060222.2 Q0IIM8-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TBC1D8BENST00000357242.10 linkc.119G>T p.Gly40Val missense_variant Exon 1 of 21 1 NM_017752.3 ENSP00000349781.5 Q0IIM8-1
TBC1D8BENST00000310452.6 linkc.119G>T p.Gly40Val missense_variant Exon 1 of 12 1 ENSP00000310675.2 Q0IIM8-3
TBC1D8BENST00000481617.6 linkc.119G>T p.Gly40Val missense_variant Exon 1 of 7 1 ENSP00000421375.1 D6RFZ2
TBC1D8BENST00000276175.7 linkc.119G>T p.Gly40Val missense_variant Exon 1 of 21 5 ENSP00000276175.3 J3KN75

Frequencies

GnomAD3 genomes
AF:
0.0000447
AC:
5
AN:
111962
Hom.:
0
Cov.:
23
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000471
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000185
AC:
32
AN:
172886
AF XY:
0.000185
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00101
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:
0.00117
GnomAD4 exome
AF:
0.0000329
AC:
36
AN:
1092894
Hom.:
0
Cov.:
30
AF XY:
0.0000334
AC XY:
12
AN XY:
358966
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
26360
American (AMR)
AF:
0.000915
AC:
32
AN:
34957
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19117
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30134
South Asian (SAS)
AF:
0.00
AC:
0
AN:
53053
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
39288
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3984
European-Non Finnish (NFE)
AF:
0.00000119
AC:
1
AN:
840109
Other (OTH)
AF:
0.0000654
AC:
3
AN:
45892
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000447
AC:
5
AN:
111962
Hom.:
0
Cov.:
23
AF XY:
0.00
AC XY:
0
AN XY:
34100
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
30799
American (AMR)
AF:
0.000471
AC:
5
AN:
10619
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2650
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3537
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2679
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
6111
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
238
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
53130
Other (OTH)
AF:
0.00
AC:
0
AN:
1513
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000718
ExAC
AF:
0.000115
AC:
14

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jan 27, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.119G>T (p.G40V) alteration is located in exon 1 (coding exon 1) of the TBC1D8B gene. This alteration results from a G to T substitution at nucleotide position 119, causing the glycine (G) at amino acid position 40 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.25
BayesDel_addAF
Benign
-0.29
T
BayesDel_noAF
Benign
-0.23
CADD
Pathogenic
26
DANN
Uncertain
0.99
DEOGEN2
Benign
0.23
T;.;T;T
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.87
D;D;D;D
M_CAP
Uncertain
0.088
D
MetaRNN
Benign
0.22
T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Uncertain
2.4
M;M;.;.
PhyloP100
9.1
PrimateAI
Uncertain
0.53
T
PROVEAN
Uncertain
-3.4
D;D;D;D
REVEL
Benign
0.28
Sift
Uncertain
0.029
D;T;D;D
Sift4G
Uncertain
0.019
D;D;D;D
Polyphen
1.0
D;.;D;.
Vest4
0.65
MutPred
0.43
Loss of disorder (P = 0.0198);Loss of disorder (P = 0.0198);Loss of disorder (P = 0.0198);Loss of disorder (P = 0.0198);
MVP
0.42
MPC
0.47
ClinPred
0.18
T
GERP RS
5.2
PromoterAI
-0.030
Neutral
Varity_R
0.72
gMVP
0.50
Mutation Taster
=92/8
polymorphism

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: rs754093308; hg19: chrX-106046202; API