14-24260555-C-T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PP2PP3_StrongPP5_Very_Strong

The NM_000359.3(TGM1):​c.652G>A​(p.Gly218Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,614,082 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 (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

TGM1
NM_000359.3 missense

Scores

12
5
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 7.75

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 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000359.3
PM2
Very rare variant in population databases, with high coverage;
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, 0.995
PP5
Variant 14-24260555-C-T is Pathogenic according to our data. Variant chr14-24260555-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 12500.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.652G>A p.Gly218Ser missense_variant Exon 4 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.652G>A p.Gly218Ser missense_variant Exon 4 of 15 1 NM_000359.3 ENSP00000206765.6 P22735-1
TGM1ENST00000544573.5 linkc.-29+1572G>A intron_variant Intron 2 of 8 2 ENSP00000439446.1 P22735-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
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
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251490
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000144
AC:
21
AN:
1461882
Hom.:
0
Cov.:
32
AF XY:
0.0000151
AC XY:
11
AN XY:
727240
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:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000153
AC:
17
AN:
1112012
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
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:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
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:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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:
0.00000478
Hom.:
0
Bravo
AF:
0.0000793
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive congenital ichthyosis 1 Pathogenic:6
Feb 07, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 20, 2017
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. -

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

- -

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

- -

Nov 23, 2022
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missene variant c.652G>A (p.Gly218Ser) in TGM1 gene has been previously reported in homozygous and compound heterozygous state in individuals affected with non-syndromic ichthyosis (Gupta A. et al., 2015; Marukian NV. et al., 2017). This variant is reported with the allele frequency (0.001%) in the gnomAD and novel in 1000 genome database. It has been submitted to ClinVar as a Pathogenic/ Likely Pathogenic variant. The amino acid Glycine at position 218 is changed to a Serine changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted to be damaging by both SIFT and PolyPhen2. The residue is conserved across species. For these reasons, this variant has been classified as Likely Pathogenic. -

not provided Pathogenic:2
Sep 03, 2020
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); 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: 31631373, 28403434, 26594337, 9326318) -

Jan 16, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 218 of the TGM1 protein (p.Gly218Ser). This variant is present in population databases (rs121918732, gnomAD 0.006%). This missense change has been observed in individuals with ichthyosis (PMID: 9326318, 26594337, 28403434, 31631373). It has also been observed to segregate with disease in related individuals. This variant is also known as p.Gly217Ser. ClinVar contains an entry for this variant (Variation ID: 12500). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TGM1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Lamellar ichthyosis Pathogenic:1
Apr 24, 2023
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.652G>A (p.Gly218Ser) results in a non-conservative amino acid change located in the 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 allele was found at a frequency of 1.2e-05 in 251490 control chromosomes. c.652G>A (aka. Gly-217-Ser) has been reported in the literature in multiple individuals affected with Ichthyosis (e.g. Laiho_1999, Gupta_2015, Marukian_2017, Hake_2022). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and all laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Congenital ichthyosiform erythroderma Pathogenic:1
-
Equipe Genetique des Anomalies du Developpement, Université de Bourgogne
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.49
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.96
D
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.99
D
M_CAP
Pathogenic
0.60
D
MetaRNN
Pathogenic
1.0
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.6
M
PhyloP100
7.7
PrimateAI
Uncertain
0.66
T
PROVEAN
Pathogenic
-5.5
D
REVEL
Pathogenic
0.92
Sift
Uncertain
0.0040
D
Sift4G
Uncertain
0.011
D
Polyphen
1.0
D
Vest4
0.95
MutPred
0.98
Loss of ubiquitination at K219 (P = 0.1516);
MVP
0.99
MPC
0.92
ClinPred
0.85
D
GERP RS
6.0
PromoterAI
0.043
Neutral
Varity_R
0.90
gMVP
0.90
Mutation Taster
=11/89
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs121918732; hg19: chr14-24729761; COSMIC: COSV99253095; COSMIC: COSV99253095; API