rs121918722

Variant names:

• chr14-24259087-C-T
• rs121918722
• NM_000359.3:c.1147G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PS3 PM1 PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_000359.3(TGM1):​c.1147G>A​(p.Val383Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,746 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 (★★). ClinVar reports functional evidence for this variant: "SCV005085987: "This variant has strong functional evidence supporting abnormal protein function. Functional studies using cultured keratinocytes from affected patient exhibited reduced transglutaminase activity and an absence of TGK protein (PMID:9359043)."" and additional evidence is available in ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TGM1 NM_000359.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 5.02
• Publications: 6 publications found

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: Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, Myriad Women’s Health, G2P
• 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

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV005085987: "This variant has strong functional evidence supporting abnormal protein function. Functional studies using cultured keratinocytes from affected patient exhibited reduced transglutaminase activity and an absence of TGK protein (PMID: 9359043)."; SCV001821463: The most pronounced variant effect results in <10% of normal transglutaminase type 1 enzyme activity (example, Petit_1997).
• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 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, lamellar ichthyosis, congenital non-bullous ichthyosiform erythroderma, self-healing collodion baby, bathing suit ichthyosis, acral self-healing collodion baby.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.883
• PP5: Variant 14-24259087-C-T is Pathogenic according to our data. Variant chr14-24259087-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 12488.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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TGM1	NM_000359.3	MANE Select	c.1147G>A	p.Val383Met	missense	Exon 7 of 15	NP_000350.1	P22735-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TGM1	ENST00000206765.11	TSL:1 MANE Select	c.1147G>A	p.Val383Met	missense	Exon 7 of 15	ENSP00000206765.6	P22735-1
	TGM1	ENST00000879556.1		c.1147G>A	p.Val383Met	missense	Exon 6 of 14	ENSP00000549615.1
	TGM1	ENST00000559136.1	TSL:5	c.220G>A	p.Val74Met	missense	Exon 3 of 7	ENSP00000453337.1	H0YLT9

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461746 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727184

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44716

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: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53338

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111978

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Autosomal recessive congenital ichthyosis 1 (5)
1	-	-	Abnormality of the skin (1)
1	-	-	Lamellar ichthyosis (1)
1	-	-	not provided (1)
1	-	-	TGM1-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	3.1	M
PhyloP100		5.0
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-2.4	N
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.69		Loss of catalytic residue at V383 (P = 0.0049)
MVP		0.97
MPC		0.92
ClinPred		0.99	D
GERP RS		4.4
Varity_R		0.70
gMVP		0.85
Mutation Taster		=16/84	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs121918722; hg19: chr14-24728293;