rs376663785

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000404.4(GLB1):c.808T>G(p.Tyr270Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,614,098 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. Y270H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9O:1

Conservation

PhyloP100: 8.93

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 19 ACMG points.

PM1

In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 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 chr3-33051988-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 198726.

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, 0.966

PP5

Variant 3-33051989-A-C is Pathogenic according to our data. Variant chr3-33051989-A-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 284172.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.808T>G	p.Tyr270Asp	missense_variant	Exon 8 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.808T>G	p.Tyr270Asp	missense_variant	Exon 8 of 16	1	NM_000404.4	ENSP00000306920.4		P16278

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152230

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000160

AC:

AN:

249468

AF XY:

0.0000148

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000353

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000198

AC:

AN:

1461868

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

727238

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:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.0000261

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.496

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74370

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41462

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68046

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00163

Hom.:

Bravo

AF:

0.0000227

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000121

AC:

ExAC

AF:

0.0000248

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Oct 21, 2015

Eurofins Ntd Llc (ga)

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 29, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published functional studies demonstrate a damaging effect: undetectable enzyme activity (Hofer et al., 2009; Higaki et al., 2011); Not observed at a significant frequency in large population cohorts (gnomAD); 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: 18937943, 20409738, 21520340, 18546276, 33737400, 22784478, 19472408, 31761138, 11511921, 32036093, 34691145) -

Feb 16, 2025

Laboratory of Genetics, Children's Clinical University Hospital Latvia

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

- -

Mucopolysaccharidosis, MPS-IV-B

Pathogenic:2

Apr 14, 2022

MGZ Medical Genetics Center

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 08, 2018

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.808T>G (p.Tyr270Asp) results in a non-conservative amino acid change located in the catalytic domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. The variant allele was found at a frequency of 2.2e-05 in 6/277174 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in GLB1 causing Mucopolysaccharidosis Type IVB (Morquio Syndrome B) (2.2e-05 vs 0.00091), allowing no conclusion about variant significance. The c.808T>G has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type IVB (Morquio Syndrome B) and GM1 gangliosidosis. These data indicate that the variant is very likely to be associated with disease. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Inborn genetic diseases

Pathogenic:1

Apr 26, 2016

Ambry Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Pathogenic:1

Nov 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 270 of the GLB1 protein (p.Tyr270Asp). This variant is present in population databases (rs376663785, gnomAD 0.005%). This missense change has been observed in individual(s) with GLB1-related conditions (PMID: 11511921, 19472408, 21520340; internal data). ClinVar contains an entry for this variant (Variation ID: 284172). 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%. 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

Apr 06, 2017

Counsyl

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

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. -

GLB1-related disorder

Other:1

GenomeConnect - GM1

Significance:not provided

Review Status:no classification provided

Collection Method:phenotyping only

Variant interpreted as Pathogenic and reported on 10-29-2018 by lab or GTR ID Centogene. GenomeConnect - GM1 assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.86

.;.;.;D

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.91

.;.;D;D

M_CAP

Pathogenic

0.76

MetaRNN

Pathogenic

0.97

D;D;D;D

MetaSVM

Pathogenic

1.1

PhyloP100

8.9

PrimateAI

Uncertain

0.76

PROVEAN

Pathogenic

-9.5

D;D;D;D

REVEL

Pathogenic

0.99

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D

Polyphen

1.0

.;.;D;.

Vest4

0.98

MVP

0.98

MPC

1.2

ClinPred

1.0

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.97

Mutation Taster

=3/97

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

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over