3-33016818-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM2PP2PP3_ModeratePP5_Very_Strong

The NM_000404.4(GLB1):c.1370G>A(p.Arg457Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000681 in 1,614,096 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

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

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 7.91

Publications

11 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 13 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

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, 0.92

PP5

Variant 3-33016818-C-T is Pathogenic according to our data. Variant chr3-33016818-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 930.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.1370G>A	p.Arg457Gln	missense_variant	Exon 14 of 16	ENST00000307363.10	NP_000395.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLB1	ENST00000307363.10 link	c.1370G>A	p.Arg457Gln	missense_variant	Exon 14 of 16	1	NM_000404.4	ENSP00000306920.4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152186

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:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000120

AC:

AN:

249530

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:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461792

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727196

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33474

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111944

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

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:

152304

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74476

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41562

American (AMR)

AF:

0.00

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.000193

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2116

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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

GM1 gangliosidosis type 3

Pathogenic:1

Aug 01, 1991

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3

Pathogenic:1

Nov 16, 2021

Myriad Genetics, Inc.

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

NM_000404.2(GLB1):c.1370G>A(R457Q) is a missense variant classified as likely pathogenic in the context of GLB1-related disorders. R457Q has been observed in cases with relevant disease (PMID: 31761138, 1353343, 16617000). Functional assessments of this variant are available in the literature (PMID: 1907800, 16617000). R457Q has been observed in population frequency databases (gnomAD: SAS 0.02%). In summary, NM_000404.2(GLB1):c.1370G>A(R457Q) is a missense variant that has functional support for pathogenicity and has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -

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

Pathogenic:1

Jul 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 457 of the GLB1 protein (p.Arg457Gln). This variant is present in population databases (rs28934886, gnomAD 0.003%). This missense change has been observed in individual(s) with GM1-gangliosidosis (PMID: 1907800, 16617000, 31761138). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is also known as 1404G>A. ClinVar contains an entry for this variant (Variation ID: 930). 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: 1907800, 11504597). For these reasons, this variant has been classified as Pathogenic. -

GM1 gangliosidosis

Pathogenic:1

Aug 16, 2022

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.1370G>A (p.Arg457Gln) results in a conservative amino acid change in 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 249530 control chromosomes (gnomAD). c.1370G>A has been reported in the literature as a biallelic genotype in individuals affected with GM1 Gangliosidosis (e.g. Yoshida_1991, Iwasaki_2006, Arash-Kaps_2019). These data indicate that the variant is likely to be associated with disease. When transfected into GLB1-null cells, the variant protein showed greater than 150-fold reduction in beta-Galactosidase activity compared to wild-type (Yoshida_1991). Two ClinVar submitters have assessed the variant since 2014: both classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Pathogenic

0.42

BayesDel_noAF

Pathogenic

0.46

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

.;.;D

M_CAP

Uncertain

0.21

MetaRNN

Pathogenic

0.92

D;D;D

MetaSVM

Pathogenic

1.0

PhyloP100

7.9

PrimateAI

Benign

0.42

PROVEAN

Uncertain

-3.3

D;D;D

REVEL

Pathogenic

0.84

Sift

Uncertain

0.0020

D;D;D

Sift4G

Uncertain

0.0030

D;D;D

Polyphen

1.0

.;.;D

Vest4

0.96

MutPred

0.73

Loss of glycosylation at T462 (P = 0.0705);.;.;

MVP

0.98

MPC

0.93

ClinPred

0.99

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.91

Mutation Taster

=9/91

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over