rs1555327550

Variant names:

• chr13-75481761-G-T
• rs1555327550
• NM_014832.5:c.7C>A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_014832.5(TBC1D4):​c.7C>A​(p.Pro3Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TBC1D4 NM_014832.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.174

Genes affected

TBC1D4 (HGNC:19165): (TBC1 domain family member 4) This gene is a member of the Tre-2/BUB2/CDC16 domain family. The protein encoded by this gene is a Rab-GTPase-activating protein, and contains two phopshotyrosine-binding domains (PTB1 and PTB2), a calmodulin-binding domain (CBD), a Rab-GTPase domain, and multiple AKT phosphomotifs. This protein is thought to play an important role in glucose homeostasis by regulating the insulin-dependent trafficking of the glucose transporter 4 (GLUT4), important for removing glucose from the bloodstream into skeletal muscle and fat tissues. Reduced expression of this gene results in an increase in GLUT4 levels at the plasma membrane, suggesting that this protein is important in intracellular retention of GLUT4 under basal conditions. When exposed to insulin, this protein is phosphorylated, dissociates from GLUT4 vesicles, resulting in increased GLUT4 at the cell surface, and enhanced glucose transport. Phosphorylation of this protein by AKT is required for proper translocation of GLUT4 to the cell surface. Individuals homozygous for a mutation in this gene are at higher risk for type 2 diabetes and have higher levels of circulating glucose and insulin levels after glucose ingestion. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2015]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.056664914).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBC1D4	NM_014832.5	c.7C>A	p.Pro3Thr	missense_variant	Exon 1 of 21	ENST00000377636.8	NP_055647.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBC1D4	ENST00000377636.8	c.7C>A	p.Pro3Thr	missense_variant	Exon 1 of 21	2	NM_014832.5	ENSP00000366863.3
TBC1D4	ENST00000431480.6	c.7C>A	p.Pro3Thr	missense_variant	Exon 1 of 20	1		ENSP00000395986.2
TBC1D4	ENST00000377625.6	c.7C>A	p.Pro3Thr	missense_variant	Exon 1 of 19	1		ENSP00000366852.2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1425574 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 708010

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Oct 25, 2016

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.058
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.67
CADD	Benign	16
DANN	Benign	0.95
DEOGEN2	Benign	0.029	.;.;T
Eigen	Benign	-0.64
Eigen_PC	Benign	-0.55
FATHMM_MKL	Benign	0.036	N
LIST_S2	Benign	0.69	T;T;T
M_CAP	Pathogenic	0.30	D
MetaRNN	Benign	0.057	T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.0	N;N;N
PrimateAI	Uncertain	0.66	T
PROVEAN	Benign	-0.11	N;N;N
REVEL	Benign	0.12
Sift	Benign	0.23	T;T;T
Sift4G	Benign	0.65	T;T;T
Polyphen		0.0	B;B;B
Vest4		0.065
MutPred		0.16		Gain of phosphorylation at P3 (P = 0.0257);Gain of phosphorylation at P3 (P = 0.0257);Gain of phosphorylation at P3 (P = 0.0257);
MVP		0.41
MPC		0.37
ClinPred		0.090	T
GERP RS		-1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.063
gMVP		0.41

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: rs1555327550; hg19: chr13-76055897;