12-82896320-A-G

Variant summary

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

The NM_152588.3(TMTC2):c.1157A>G(p.Gln386Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TMTC2 NM_152588.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0550

Genes affected

TMTC2 (HGNC:25440): (transmembrane O-mannosyltransferase targeting cadherins 2) The protein encoded by this gene is an integral membrane protein localized to the endoplasmic reticulum (ER). The encoded protein contains many tetratricopeptide repeats, sequences known for being involved in protein-protein interactions. This protein binds both the calcium uptake pump SERCA2B and the carbohydrate-binding chaperone calnexin, and it appears to play a role in calcium homeostasis in the ER. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2016]

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=0.053996056).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMTC2	NM_152588.3	c.1157A>G	p.Gln386Arg	missense_variant	3/12	ENST00000321196.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMTC2	ENST00000321196.8	c.1157A>G	p.Gln386Arg	missense_variant	3/12	1	NM_152588.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251324 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135822

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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

Jun 03, 2022

The c.1157A>G (p.Q386R) alteration is located in exon 3 (coding exon 3) of the TMTC2 gene. This alteration results from a A to G substitution at nucleotide position 1157, causing the glutamine (Q) at amino acid position 386 to be replaced by an arginine (R). 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	0.069
BayesDel_addAF	Benign	-0.35	T
BayesDel_noAF	Benign	-0.56
Cadd	Benign	9.5
Dann	Benign	0.74
DEOGEN2	Benign	0.00023	T;.;T
Eigen	Benign	-0.89
Eigen_PC	Benign	-0.87
FATHMM_MKL	Benign	0.22	N
LIST_S2	Benign	0.75	T;T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.054	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.3	L;.;.
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.030	N;N;N
REVEL	Benign	0.0070
Sift	Benign	0.23	T;T;T
Sift4G	Benign	0.56	T;T;T
Polyphen		0.0	B;B;.
Vest4		0.086
MutPred		0.41		Loss of helix (P = 0.028);Loss of helix (P = 0.028);.;
MVP		0.33
MPC		0.16
ClinPred		0.039	T
GERP RS		-1.3
Varity_R		0.050
gMVP		0.55

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: rs748537146; hg19: chr12-83290099;