chr3-33068881-T-G
Variant summary
Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2PP2PP5_Very_Strong
The NM_000404.4(GLB1):c.335A>C(p.His112Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,614,038 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. H112Y) has been classified as Likely benign.
Frequency
Consequence
NM_000404.4 missense
Scores
Clinical Significance
Conservation
Publications
- GM1 gangliosidosisInheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, ClinGen
- GM1 gangliosidosis type 3Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
- mucopolysaccharidosis type 4BInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- GM1 gangliosidosis type 1Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
- GM1 gangliosidosis type 2Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
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ACMG classification
Our verdict: Pathogenic. The variant received 11 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152148Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000120 AC: 3AN: 249516 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.0000205 AC: 30AN: 1461890Hom.: 0 Cov.: 32 AF XY: 0.0000179 AC XY: 13AN XY: 727244 show subpopulations
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152148Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74322 show subpopulations
ClinVar
Submissions by phenotype
GM1 gangliosidosis Pathogenic:1
Variant summary: GLB1 c.335A>C (p.His112Pro) results in a non-conservative amino acid change located in the (Trans)glycosidases domain (IPR017853) of the encoded protein sequence. Four 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 249516 control chromosomes (gnomAD). c.335A>C has been reported in the literature in individuals affected with GM1 Gangliosidosis (Hofer_2010, Lawrence_2019, Koya Kutty_2022). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (Hofer_2010). The following publications have been ascertained in the context of this evaluation (PMID: 20175788, 35937492, 31720227). ClinVar contains an entry for this variant (Variation ID: 555030). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B Pathogenic:1
This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 112 of the GLB1 protein (p.His112Pro). This variant is present in population databases (rs753965226, gnomAD 0.004%). This missense change has been observed in individual(s) with GM1-gangliosidosis (PMID: 20175788, 35937492). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 555030). 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) performed at Invitae indicates that this missense variant is expected to disrupt GLB1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GLB1 function (PMID: 20175788). For these reasons, this variant has been classified as Pathogenic. -
Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 Uncertain:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at