rs121918716

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_000359.3(TGM1):​c.424C>T​(p.Arg142Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000682 in 1,613,938 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R142H) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

TGM1
NM_000359.3 missense

Scores

15
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 6.48
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-24261778-C-T is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.996
PP5
Variant 14-24261779-G-A is Pathogenic according to our data. Variant chr14-24261779-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 12483.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-24261779-G-A is described in UniProt as null. Variant chr14-24261779-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TGM1NM_000359.3 linkc.424C>T p.Arg142Cys missense_variant Exon 3 of 15 ENST00000206765.11 NP_000350.1 P22735-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TGM1ENST00000206765.11 linkc.424C>T p.Arg142Cys missense_variant Exon 3 of 15 1 NM_000359.3 ENSP00000206765.6 P22735-1
TGM1ENST00000544573.5 linkc.-29+348C>T intron_variant Intron 2 of 8 2 ENSP00000439446.1 P22735-2
TGM1ENST00000558074.1 linkc.*19C>T downstream_gene_variant 5 ENSP00000453840.1 H0YN27

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152054
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1461884
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727238
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000629
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152054
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74254
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000193
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000557
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive congenital ichthyosis 1 Pathogenic:6
Jan 01, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 13, 2020
Natera, Inc.
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Sep 01, 1997
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Jul 19, 2017
Counsyl
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 20, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Lamellar ichthyosis Pathogenic:1
Oct 19, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: TGM1 c.424C>T (p.Arg142Cys) results in a non-conservative amino acid change located in the Transglutaminase, N-terminal domain (IPR001102) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251442 control chromosomes. c.424C>T has been reported in the literature in multiple individuals affected with Lamellar Ichthyosis (example, Huber_1995, Laiho_1999, Mir-Bonafe_2015). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal Transglutaminase enzyme activity in vitro (example, Huber_1997). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1
Dec 11, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 142 of the TGM1 protein (p.Arg142Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal recessive congenital ichthyosis syndromes (PMID: 7824952, 9326318, 24314425, 26076875). ClinVar contains an entry for this variant (Variation ID: 12483). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TGM1 protein function. Experimental studies have shown that this missense change affects TGM1 function (PMID: 20663883, 22258055). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.54
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.98
D
Eigen
Pathogenic
0.74
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Pathogenic
0.99
D
M_CAP
Pathogenic
0.68
D
MetaRNN
Pathogenic
1.0
D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.1
M
PrimateAI
Uncertain
0.58
T
PROVEAN
Pathogenic
-7.3
D
REVEL
Pathogenic
0.97
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.98
MutPred
0.98
Loss of disorder (P = 0.0436);
MVP
0.99
MPC
1.1
ClinPred
1.0
D
GERP RS
5.2
Varity_R
0.92
gMVP
0.93

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121918716; hg19: chr14-24730985; API