rs72555367

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PM5PP2PP3_ModeratePP5_Very_Strong

The NM_000404.4(GLB1):c.1313G>A(p.Gly438Glu) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,888 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G438V) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 5.65

Publications

16 publications found

Variant links:

Genes affected

GLB1 (HGNC:4298): (galactosidase beta 1) This gene encodes a member of the glycosyl hydrolase 35 family of proteins. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the mature lysosomal enzyme. This enzyme catalyzes the hydrolysis of a terminal beta-linked galactose residue from ganglioside substrates and other glycoconjugates. Mutations in this gene may result in GM1-gangliosidosis and Morquio B syndrome. [provided by RefSeq, Nov 2015]

GLB1 Gene-Disease associations (from GenCC):

GM1 gangliosidosis
Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, ClinGen
GM1 gangliosidosis type 3
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
mucopolysaccharidosis type 4B
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
GM1 gangliosidosis type 1
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
GM1 gangliosidosis type 2
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp

GLB1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_000404.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr3-33018482-C-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3753905.Status of the report is criteria_provided_single_submitter, 1 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 110 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: 0.79419 (below the threshold of 3.09). Trascript score misZ: 1.1264 (below the threshold of 3.09). GenCC associations: The gene is linked to mucopolysaccharidosis type 4B, GM1 gangliosidosis, GM1 gangliosidosis type 2, GM1 gangliosidosis type 3, GM1 gangliosidosis type 1.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.901

PP5

Variant 3-33018482-C-T is Pathogenic according to our data. Variant chr3-33018482-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 940.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLB1	NM_000404.4 link	c.1313G>A	p.Gly438Glu	missense_variant	Exon 13 of 16	ENST00000307363.10	NP_000395.3	P16278

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLB1	ENST00000307363.10 link	c.1313G>A	p.Gly438Glu	missense_variant	Exon 13 of 16	1	NM_000404.4	ENSP00000306920.4		P16278

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112010

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Oct 23, 2020

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 03, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Functional studies found this variant is associated with significantly reduced beta-galactosidase activity (Hofer et al., 2009); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33737400, 10841810, 19472408, 20629163, 15986423, 23831247, 22033734, 31216405) -

Jan 01, 2020

CeGaT Center for Human Genetics Tuebingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mucopolysaccharidosis, MPS-IV-B

Pathogenic:1

May 04, 2021

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

GM1 gangliosidosis

Pathogenic:1

Feb 24, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: GLB1 c.1313G>A (p.Gly438Glu) results in a non-conservative amino acid change located in the Beta-galactosidase, first all-beta domain (IPR048912) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 249588 control chromosomes. c.1313G>A has been reported in the literature in multiple individuals affected with GM1 Gangliosidosis and related conditions (Hofer_2009, Fantur_2011). These data indicate that the variant is very likely to 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_2009).The following publications have been ascertained in the context of this evaluation (PMID: 19472408, 22033734). ClinVar contains an entry for this variant (Variation ID: 940). Based on the evidence outlined above, the variant was classified as pathogenic. -

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B

Pathogenic:1

Sep 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 438 of the GLB1 protein (p.Gly438Glu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with GM1 gangliosidosis and mucopolysaccharidosis IVB (PMID: 10841810, 19472408, 21497194, 23831247, 26646981). ClinVar contains an entry for this variant (Variation ID: 940). 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 GLB1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GLB1 function (PMID: 19472408). 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

Pathogenic:1

Jul 03, 2012

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Spondyloepiphyseal dysplasia

Pathogenic:1

Mar 09, 2022

Génétique des Maladies du Développement, Hospices Civils de Lyon

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

recurrent pathogenic variant -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.48

BayesDel_addAF

Pathogenic

0.42

BayesDel_noAF

Pathogenic

0.36

CADD

Benign

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.87

.;.;D

M_CAP

Uncertain

0.19

MetaRNN

Pathogenic

0.90

D;D;D

MetaSVM

Uncertain

0.58

PhyloP100

5.7

PrimateAI

Benign

0.45

PROVEAN

Pathogenic

-5.0

D;D;D

REVEL

Pathogenic

0.82

Sift

Benign

0.082

T;T;T

Sift4G

Benign

0.18

T;T;T

Polyphen

1.0

.;.;D

Vest4

0.94

MutPred

0.67

Loss of glycosylation at S434 (P = 0.0398);.;.;

MVP

0.97

MPC

0.99

ClinPred

0.99

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.84

Mutation Taster

=12/88

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over