rs1555305725

Positions:

• chr14-24254768-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000359.3(TGM1):​c.1984C>T​(p.Gln662*) variant causes a stop gained change. 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TGM1 NM_000359.3 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 6.93

Genes affected

TGM1 (HGNC:11777): (transglutaminase 1) The protein encoded by this gene is a membrane protein that catalyzes the addition of an alkyl group from an akylamine to a glutamine residue of a protein, forming an alkylglutamine in the protein. This protein alkylation leads to crosslinking of proteins and catenation of polyamines to proteins. This gene contains either one or two copies of a 22 nt repeat unit in its 3' UTR. Mutations in this gene have been associated with autosomal recessive lamellar ichthyosis (LI) and nonbullous congenital ichthyosiform erythroderma (NCIE). [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 14-24254768-G-A is Pathogenic according to our data. Variant chr14-24254768-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 558187.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TGM1	NM_000359.3	c.1984C>T	p.Gln662*	stop_gained	13/15	ENST00000206765.11	NP_000350.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TGM1	ENST00000206765.11	c.1984C>T	p.Gln662*	stop_gained	13/15	1	NM_000359.3	ENSP00000206765.6
TGM1	ENST00000544573.5	c.658C>T	p.Gln220*	stop_gained	7/9	2		ENSP00000439446.1
TGM1	ENST00000559669.1	c.142C>T	p.Gln48*	stop_gained	2/3	3		ENSP00000453701.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive congenital ichthyosis 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 11, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 03, 2018	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 23, 2023

This sequence change creates a premature translational stop signal (p.Gln662*) in the TGM1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TGM1 are known to be pathogenic (PMID: 18948357, 19241467). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 558187). This variant is also known as Q661X. This premature translational stop signal has been observed in individual(s) with lamellar ichthyosis (PMID: 10886517). This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	43
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.92
GERP RS		4.5

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: rs1555305725; hg19: chr14-24723974;