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
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 17 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152200Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251490 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000144 AC: 21AN: 1461882Hom.: 0 Cov.: 32 AF XY: 0.0000151 AC XY: 11AN XY: 727240 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152200Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74338 show subpopulations
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This submission and the accompanying classification are no longer maintained by the submitter.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. -
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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
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) -
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
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
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at