rs121918731

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PM5PP2PP3_ModeratePP5_Very_Strong

The NM_000359.3(TGM1):​c.919C>T​(p.Arg307Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,613,094 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. R307Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

TGM1
NM_000359.3 missense

Scores

7
7
3

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 1.23

Publications

17 publications found
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]
TGM1 Gene-Disease associations (from GenCC):
  • autosomal recessive congenital ichthyosis 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, PanelApp Australia, Genomics England PanelApp
  • acral self-healing collodion baby
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • bathing suit ichthyosis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital non-bullous ichthyosiform erythroderma
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • lamellar ichthyosis
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • self-healing collodion baby
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in NM_000359.3
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-24259769-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 372534.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 81 curated pathogenic missense variants (we use a threshold of 10). The gene has 20 curated benign missense variants. Gene score misZ: -0.060191 (below the threshold of 3.09). Trascript score misZ: 1.7514 (below the threshold of 3.09). GenCC associations: The gene is linked to autosomal recessive congenital ichthyosis 1, acral self-healing collodion baby, bathing suit ichthyosis, congenital non-bullous ichthyosiform erythroderma, lamellar ichthyosis, self-healing collodion baby.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.863
PP5
Variant 14-24259769-G-A is Pathogenic according to our data. Variant chr14-24259769-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 12499.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000359.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TGM1
NM_000359.3
MANE Select
c.919C>Tp.Arg307Trp
missense
Exon 6 of 15NP_000350.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TGM1
ENST00000206765.11
TSL:1 MANE Select
c.919C>Tp.Arg307Trp
missense
Exon 6 of 15ENSP00000206765.6
TGM1
ENST00000559136.1
TSL:5
c.-9C>T
5_prime_UTR_premature_start_codon_gain
Exon 2 of 7ENSP00000453337.1
TGM1
ENST00000559136.1
TSL:5
c.-9C>T
5_prime_UTR
Exon 2 of 7ENSP00000453337.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152026
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000201
AC:
5
AN:
248966
AF XY:
0.0000222
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000164
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000178
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1460950
Hom.:
0
Cov.:
32
AF XY:
0.0000124
AC XY:
9
AN XY:
726762
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44676
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.000302
AC:
12
AN:
39690
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86198
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52828
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000809
AC:
9
AN:
1111840
Other (OTH)
AF:
0.00
AC:
0
AN:
60364
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152144
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41490
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10588
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67996
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive congenital ichthyosis 1 Pathogenic:5
Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Feb 26, 2018
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Jul 30, 2023
Baylor Genetics
Significance: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

Aug 01, 2001
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Lamellar ichthyosis Pathogenic:1
Aug 23, 2022
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.919C>T (p.Arg307Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 248966 control chromosomes (gnomAD). c.919C>T has been reported in the literature as a biallelic genotype in multiple individuals affected with Lamellar Ichthyosis, predominantly from individuals of East Asian descent (e.g. Akiyama_2001, Muramatsu_2004, Sakai_2009, Yamamoto_2012, Yang_2001). These data indicate that the variant is very likely to be associated with disease. When TGase 1 activity was assayed in cultured keratocytes from a compound heterozygous proband and their unaffected carrier parent, there was 5% activity in the proband and 50% activity in the carrier parent, suggesting the variant may have limited functionality (Yang_2001). Four ClinVar submitters have assessed the variant since 2014: one classified the variant as likely pathogenic and three as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.

not provided Pathogenic:1
Jan 08, 2023
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 tryptophan, which is neutral and slightly polar, at codon 307 of the TGM1 protein (p.Arg307Trp). This variant is present in population databases (rs121918731, gnomAD 0.02%). This missense change has been observed in individuals with lamellar ichthyosis and self-improving collodion ichthyosis (PMID: 11407995, 11511296, 19262603, 20167857, 21895619, 24419105). ClinVar contains an entry for this variant (Variation ID: 12499). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TGM1 protein function. For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg307 amino acid residue in TGM1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16968736, 19863506, 26076875, 27025581, 28403434). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.32
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Pathogenic
0.23
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.82
D
Eigen
Uncertain
0.19
Eigen_PC
Benign
0.10
FATHMM_MKL
Uncertain
0.81
D
M_CAP
Pathogenic
0.70
D
MetaRNN
Pathogenic
0.86
D
MetaSVM
Uncertain
0.46
D
MutationAssessor
Benign
1.9
L
PhyloP100
1.2
PrimateAI
Uncertain
0.67
T
PROVEAN
Pathogenic
-5.0
D
REVEL
Pathogenic
0.76
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.0040
D
Polyphen
1.0
D
Vest4
0.60
MVP
0.94
MPC
0.92
ClinPred
0.93
D
GERP RS
3.0
PromoterAI
0.011
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.29
gMVP
0.70
Mutation Taster
=21/79
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs121918731; hg19: chr14-24728975; COSMIC: COSV105068815; COSMIC: COSV105068815; API