13-75299375-G-T

Position:

• chr13-75299375-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_014832.5(TBC1D4):​c.3111C>A​(p.Asp1037Glu) 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TBC1D4 NM_014832.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.36

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30696923).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TBC1D4	NM_014832.5	c.3111C>A	p.Asp1037Glu	missense_variant	17/21	ENST00000377636.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TBC1D4	ENST00000377636.8	c.3111C>A	p.Asp1037Glu	missense_variant	17/21	2	NM_014832.5	A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 24, 2023

The c.3111C>A (p.D1037E) alteration is located in exon 17 (coding exon 17) of the TBC1D4 gene. This alteration results from a C to A substitution at nucleotide position 3111, causing the aspartic acid (D) at amino acid position 1037 to be replaced by a glutamic acid (E). 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	Uncertain	0.46
BayesDel_addAF	Benign	-0.023	T
BayesDel_noAF	Benign	-0.27
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.073	.;.;.;T
Eigen	Benign	-0.096
Eigen_PC	Benign	0.029
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.90	D;D;D;D
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.31	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.99	.;.;.;L
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.80	D
PROVEAN	Benign	-1.3	.;N;N;N
REVEL	Benign	0.19
Sift	Benign	0.15	.;T;T;T
Sift4G	Benign	0.39	.;T;T;T
Polyphen		0.052, 0.43, 0.99	.;B;B;D
Vest4		0.84, 0.85, 0.82
MutPred		0.50		.;.;.;Gain of helix (P = 0.0854);
MVP		0.58
MPC		1.1
ClinPred		0.80	D
GERP RS		3.9
Varity_R		0.19
gMVP		0.53

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr13-75873511;