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
Consequence
NM_000359.3 missense
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 15 ACMG points.
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 | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TGM1 | NM_000359.3 | MANE Select | c.919C>T | p.Arg307Trp | missense | Exon 6 of 15 | NP_000350.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| TGM1 | ENST00000206765.11 | TSL:1 MANE Select | c.919C>T | p.Arg307Trp | missense | Exon 6 of 15 | ENSP00000206765.6 | ||
| TGM1 | ENST00000559136.1 | TSL:5 | c.-9C>T | 5_prime_UTR_premature_start_codon_gain | Exon 2 of 7 | ENSP00000453337.1 | |||
| TGM1 | ENST00000559136.1 | TSL:5 | c.-9C>T | 5_prime_UTR | Exon 2 of 7 | ENSP00000453337.1 |
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 152026Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000201 AC: 5AN: 248966 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.0000157 AC: 23AN: 1460950Hom.: 0 Cov.: 32 AF XY: 0.0000124 AC XY: 9AN XY: 726762 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152144Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74360 show subpopulations
ClinVar
Submissions by phenotype
Autosomal recessive congenital ichthyosis 1 Pathogenic:5
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.
Lamellar ichthyosis Pathogenic:1
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
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at