rs781006633

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_StrongPP5_Very_Strong

The NM_000359.3(TGM1):​c.791G>A​(p.Arg264Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,614,068 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. R264W) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

TGM1
NM_000359.3 missense

Scores

9
7
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 2.03

Publications

5 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 17 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000359.3
PM5
Other missense variant is known to change same aminoacid residue: Variant chr14-24260026-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 372532.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, 0.984
PP5
Variant 14-24260025-C-T is Pathogenic according to our data. Variant chr14-24260025-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 312984.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TGM1NM_000359.3 linkc.791G>A p.Arg264Gln missense_variant Exon 5 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.791G>A p.Arg264Gln missense_variant Exon 5 of 15 1 NM_000359.3 ENSP00000206765.6 P22735-1
TGM1ENST00000559136.1 linkc.-137G>A 5_prime_UTR_variant Exon 1 of 7 5 ENSP00000453337.1 H0YLT9
TGM1ENST00000544573.5 linkc.-28-1637G>A intron_variant Intron 2 of 8 2 ENSP00000439446.1 P22735-2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152204
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:
0.000578
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000278
AC:
7
AN:
251452
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1461864
Hom.:
0
Cov.:
33
AF XY:
0.0000165
AC XY:
12
AN XY:
727232
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1112000
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.438
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.0000263
AC:
4
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000578
AC:
3
AN:
5188
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000451
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000412
AC:
5

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Jan 19, 2024
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 glutamine, which is neutral and polar, at codon 264 of the TGM1 protein (p.Arg264Gln). This variant is present in population databases (rs781006633, gnomAD 0.02%). This missense change has been observed in individual(s) with congenital ichthyosis (PMID: 16968736, 30950025). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 312984). 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 with a positive predictive value of 95%. Experimental studies have shown that this missense change affects TGM1 function (PMID: 19212342). This variant disrupts the p.Arg264 amino acid residue in TGM1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16968736, 27025581, 28403434). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Aug 12, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported with a second TGM1 variant, phase unknown, in a patient with congenital ichthyosis (PMID: 16968736); Published functional studies demonstrate diminished TGM1 enzyme activity (PMID: 19212342); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34426522, 27025581, 34671977, 28403434, 30950025, 36262015, 19212342, 16968736) -

Lamellar ichthyosis Pathogenic:1
Jul 27, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TGM1 c.791G>A (p.Arg264Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251452 control chromosomes (gnomAD). c.791G>A has been reported in the literature as a compound heterozygous genotype in individuals affected with Lamellar Ichthyosis, including at least one case where it was confirmed to be in trans with a pathogenic variant (e.g. Oji_2006, Hu_2019). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function and found the variant results in <10% of normal activity and exhibits a slight improvement in activity at decreased temperatures (approximately 15% of WT at 31C) (Aufenvenne_2009). The following publications have been ascertained in the context of this evaluation (PMID: 19212342, 30950025, 16968736). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as likely pathogenic, and one submitter classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Autosomal recessive congenital ichthyosis 1 Pathogenic:1
Feb 10, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.22
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
28
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.91
D
Eigen
Pathogenic
0.73
Eigen_PC
Uncertain
0.65
FATHMM_MKL
Uncertain
0.91
D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Pathogenic
0.94
D
MutationAssessor
Pathogenic
3.4
M
PhyloP100
2.0
PrimateAI
Uncertain
0.51
T
PROVEAN
Uncertain
-2.9
D
REVEL
Pathogenic
0.71
Sift
Uncertain
0.011
D
Sift4G
Uncertain
0.031
D
Polyphen
1.0
D
Vest4
0.89
MutPred
0.92
Gain of sheet (P = 0.1451);
MVP
0.97
MPC
0.93
ClinPred
0.94
D
GERP RS
5.4
PromoterAI
0.0090
Neutral
Varity_R
0.30
gMVP
0.79
Mutation Taster
=22/78
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs781006633; hg19: chr14-24729231; API