20-38131129-C-G

Variant names:

• chr20-38131129-C-G
• NM_004613.4:c.1877G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_004613.4(TGM2):​c.1877G>C​(p.Gly626Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TGM2 NM_004613.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.48
• Publications: 0 publications found

Genes affected

TGM2 (HGNC:11778): (transglutaminase 2) Transglutaminases are enzymes that catalyze the crosslinking of proteins by epsilon-gamma glutamyl lysine isopeptide bonds. While the primary structure of transglutaminases is not conserved, they all have the same amino acid sequence at their active sites and their activity is calcium-dependent. The protein encoded by this gene acts as a monomer, is induced by retinoic acid, and appears to be involved in apoptosis. Finally, the encoded protein is the autoantigen implicated in celiac disease. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

TGM2 Gene-Disease associations (from GenCC):

• type 2 diabetes mellitus

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGM2	NM_004613.4	c.1877G>C	p.Gly626Ala	missense_variant	Exon 12 of 13	ENST00000361475.7	NP_004604.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGM2	ENST00000361475.7	c.1877G>C	p.Gly626Ala	missense_variant	Exon 12 of 13	1	NM_004613.4	ENSP00000355330.2
TGM2	ENST00000469269.1	n.1522G>C		non_coding_transcript_exon_variant	Exon 2 of 3	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jun 16, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1877G>C (p.G626A) alteration is located in exon 12 (coding exon 12) of the TGM2 gene. This alteration results from a G to C substitution at nucleotide position 1877, causing the glycine (G) at amino acid position 626 to be replaced by an alanine (A). 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	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.39	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		7.5
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-5.9	D
REVEL	Pathogenic	0.71
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.82		Loss of disorder (P = 0.1364);
MVP		0.76
MPC		0.88
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.94
Mutation Taster		=14/86	disease causing

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

Other links and lift over

hg19: chr20-36759531;