X-106822144-T-C

Position:

• chrX-106822144-T-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_017752.3(TBC1D8B):​c.528T>C​(p.Gly176=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000912 in 1,096,761 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 9.1e-7 (0 hom. 1 hem.)
• Consequence: TBC1D8B NM_017752.3 synonymous
• Clinical Significance: Uncertain significance no assertion criteria provided U:2
• Conservation: PhyloP100: -0.859

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]

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]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BP7: Synonymous conserved (PhyloP=-0.859 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TBC1D8B	NM_017752.3	c.528T>C	p.Gly176=	synonymous_variant	4/21	ENST00000357242.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TBC1D8B	ENST00000357242.10	c.528T>C	p.Gly176=	synonymous_variant	4/21	1	NM_017752.3	P2

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD3 exomes AF: 0.00000550 AC: 1 AN: 181776 Hom.: 0 AF XY: 0.0000150 AC XY: 1 AN XY: 66544

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 SAS exome AF: 0.0000535

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 9.12e-7 AC: 1 AN: 1096761 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 1 AN XY: 362561

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000186

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: no assertion criteria provided

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, flagged submission	literature only	Richard Lifton Laboratory, Yale University School of Medicine	-	- -
Uncertain significance, no assertion criteria provided	literature only	Richard Lifton Laboratory, Yale University School of Medicine	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	1.5
DANN	Benign	0.67

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

Other links and lift over

dbSNP: rs483352744; hg19: chrX-106065374;