X-106822128-G-A

Position:

chrX-106822128-G-A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_017752.3(TBC1D8B):c.512G>A(p.Arg171Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000149 in 1,208,054 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 10 hemizygotes in GnomAD. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000090 ( 0 hom., 0 hem., cov: 23)

Exomes 𝑓: 0.000015 ( 0 hom. 10 hem. )

Consequence

TBC1D8B
NM_017752.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.63

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 links:

MORC4 (HGNC:23485): (MORC family CW-type zinc finger 4) In human, the four current members of the microrchidia (morc) gene family share an N-terminal ATPase-like ATP-binding region and a CW four-cysteine zinc-finger motif. The protein encoded by this gene also has a nuclear matrix binding domain and a two-stranded coiled-coil motif near its C-terminus. This gene is widely expressed at low levels in normal tissues and has elevated expression in placenta and testis. Alternative splicing results in multiple transcript variants encoding distinct proteins. [provided by RefSeq, Jan 2010]

MORC4 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High Hemizygotes in GnomAdExome4 at 10 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TBC1D8B	NM_017752.3 linkuse as main transcript	c.512G>A	p.Arg171Gln	missense_variant	4/21	ENST00000357242.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TBC1D8B	ENST00000357242.10 linkuse as main transcript	c.512G>A	p.Arg171Gln	missense_variant	4/21	1	NM_017752.3	P2	Q0IIM8-1

Frequencies

GnomAD3 genomes

AF:

0.00000900

AC:

AN:

111122

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

33398

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:

0.000286

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

GnomAD3 exomes

AF:

0.0000110

AC:

AN:

182215

Hom.:

AF XY:

0.0000298

AC XY:

AN XY:

67021

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000368

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000123

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000155

AC:

AN:

1096932

Hom.:

Cov.:

AF XY:

0.0000276

AC XY:

AN XY:

362740

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000285

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000994

Gnomad4 SAS exome

AF:

0.0000742

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000951

Gnomad4 OTH exome

AF:

0.0000217

GnomAD4 genome

AF:

0.00000900

AC:

AN:

111122

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

33398

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000286

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 06, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with TBC1D8B-related conditions. 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 sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 171 of the TBC1D8B protein (p.Arg171Gln). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.0046

BayesDel_noAF

Benign

-0.13

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.81

D;.;D;D

FATHMM_MKL

Uncertain

0.95

LIST_S2

Pathogenic

0.98

D;D;D;D

M_CAP

Uncertain

0.16

MetaRNN

Uncertain

0.49

T;T;T;T

MetaSVM

Uncertain

0.60

MutationAssessor

Benign

1.6

L;L;.;.

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-2.8

D;D;D;D

REVEL

Uncertain

0.64

Sift

Uncertain

0.0030

D;D;D;D

Sift4G

Uncertain

0.010

D;D;D;D

Polyphen

0.98

D;.;P;.

Vest4

0.59

MutPred

0.54

Gain of ubiquitination at K169 (P = 0.0708);Gain of ubiquitination at K169 (P = 0.0708);Gain of ubiquitination at K169 (P = 0.0708);Gain of ubiquitination at K169 (P = 0.0708);

MVP

0.51

MPC

0.45

ClinPred

0.78

GERP RS

5.3

Varity_R

0.57

gMVP

0.32

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over