rs367699137
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000359.3(TGM1):c.788G>A(p.Trp263*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000378 in 1,614,108 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000359.3 stop_gained
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive congenital ichthyosis 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, PanelApp Australia, Genomics England PanelApp
- acral self-healing collodion babyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- bathing suit ichthyosisInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- congenital non-bullous ichthyosiform erythrodermaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- lamellar ichthyosisInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- self-healing collodion babyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TGM1 | ENST00000206765.11 | c.788G>A | p.Trp263* | stop_gained | Exon 5 of 15 | 1 | NM_000359.3 | ENSP00000206765.6 | ||
| TGM1 | ENST00000559136.1 | c.-140G>A | 5_prime_UTR_variant | Exon 1 of 7 | 5 | ENSP00000453337.1 | ||||
| TGM1 | ENST00000544573.5 | c.-28-1640G>A | intron_variant | Intron 2 of 8 | 2 | ENSP00000439446.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152242Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000278 AC: 7AN: 251446 AF XY: 0.0000294 show subpopulations
GnomAD4 exome AF: 0.0000404 AC: 59AN: 1461866Hom.: 0 Cov.: 33 AF XY: 0.0000413 AC XY: 30AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152242Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74382 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Autosomal recessive congenital ichthyosis 1 Pathogenic:6
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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. -
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. Regardless of the mechanism, a variant called homozygous is by default in trans.The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000419403 /PMID: 9544844). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
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not provided Pathogenic:2
The W263X variant in the TGM1 gene has been reported previously in patients of Tunisian, Portugese, and Moroccan ancestry in association with lamellar ichthyosis (Hennies et al., 1998; Louhichi et al., 2013; Esposito et al., 2013). It is suggested that the W263X variant may be a recurrent variant in patients with severe LI of Tunisian ancestry and haplotype analysis has shown consistency with founder effects (Louichi et al., 2013; Esposito et al., 2013). W263X was not observed at any significant frequency in approximately 6,500 individuals of European and African American ancestry by the NHLBI Exome Sequencing Project. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. In addition, decreased protein production due to the W263X variant results in loss of the catalytic triad of the transamidation catalytic core domain (Cserhalmi-Friedman et al., 2000; Terrinoni et al., 2012). Therefore, we consider the W263X variant to be pathogenic. -
This sequence change creates a premature translational stop signal (p.Trp263*) in the TGM1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in TGM1 are known to be pathogenic (PMID: 18948357, 19241467). This variant is present in population databases (rs367699137, ExAC 0.002%). This premature translational stop signal has been observed in individuals with congenital lamellar ichthyosis (PMID: 23192619). ClinVar contains an entry for this variant (Variation ID: 419403). For these reasons, this variant has been classified as Pathogenic. -
Lamellar ichthyosis Pathogenic:1
Variant summary: TGM1 c.788G>A (p.Trp263X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 2.8e-05 in 251446 control chromosomes (gnomAD). c.788G>A has been reported in the literature in multiple individuals affected with Lamellar Ichthyosis (example: Rodriguez-Pazos_2011 and Diociaiuti_2016). These data indicate that the variant is very likely to be associated with disease. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at