rs376663785

chr3-33051989-A-Cchr3-33051989-A-G

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PS1_ModeratePM1PM2PM5PP3_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 nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y270C) has been classified as Likely pathogenic.

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:8O:1

Conservation

PhyloP100: 8.93

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 20 ACMG points.

PS1

Transcript NM_000404.4 (GLB1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt

PM1

In a hotspot region, there are 4 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 id is 198726.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=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 [Likely_pathogenic]. Clinvar id is 284172.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-33051989-A-C is described in Lovd as [Pathogenic]. Variant chr3-33051989-A-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GLB1	NM_000404.4 linkuse as main transcript	c.808T>G	p.Tyr270Asp	missense_variant	8/16	ENST00000307363.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GLB1	ENST00000307363.10 linkuse as main transcript	c.808T>G	p.Tyr270Asp	missense_variant	8/16	1	NM_000404.4	P2

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

GnomAD3 exomes

AF:

0.0000160

AC:

AN:

249468

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135340

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 SAS 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

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000261

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.00200

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:8Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 21, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 29, 2022	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) -

Mucopolysaccharidosis, MPS-IV-B

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 08, 2018	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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Apr 14, 2022	- -

Inborn genetic diseases

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 26, 2016

- -

Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Apr 06, 2017

- -

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 13, 2023

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; Invitae). ClinVar contains an entry for this variant (Variation ID: 284172). 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%. For these reasons, this variant has been classified as Pathogenic. -

GLB1-related disorder

Other:1

not provided, no classification provided

phenotyping only

GenomeConnect - GM1

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

Dann

Uncertain

0.99

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

1.0

M_CAP

Pathogenic

0.76

MetaRNN

Pathogenic

0.97

D;D;D;D

MetaSVM

Pathogenic

1.1

MutationTaster

Benign

1.0

D;D;D;D

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

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over