rs398123351

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.1769G>A​(p.Arg590His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,613,732 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. R590C) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

14
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 7.83

Publications

8 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

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 5 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 chr3-32997311-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 194596.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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, 0.986
PP5
Variant 3-32997310-C-T is Pathogenic according to our data. Variant chr3-32997310-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 92901.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
GLB1NM_000404.4 linkc.1769G>A p.Arg590His missense_variant Exon 16 of 16 ENST00000307363.10 NP_000395.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLB1ENST00000307363.10 linkc.1769G>A p.Arg590His missense_variant Exon 16 of 16 1 NM_000404.4 ENSP00000306920.4
GLB1ENST00000307377.12 linkc.1376G>A p.Arg459His missense_variant Exon 13 of 13 1 ENSP00000305920.8
GLB1ENST00000399402.7 linkc.1679G>A p.Arg560His missense_variant Exon 16 of 16 2 ENSP00000382333.2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152160
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
249130
AF XY:
0.0000222
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:
0.0000267
AC:
39
AN:
1461572
Hom.:
0
Cov.:
31
AF XY:
0.0000303
AC XY:
22
AN XY:
727092
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5536
European-Non Finnish (NFE)
AF:
0.0000306
AC:
34
AN:
1111992
Other (OTH)
AF:
0.00
AC:
0
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
3
6
8
11
14
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000263
AC:
4
AN:
152160
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74318
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.512
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000182
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.00000827
AC:
1
EpiCase
AF:
0.000218
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Nov 06, 2013
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Progressive familial intrahepatic cholestasis Pathogenic:1
Mar 18, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ABCB4 c.1769G>A (p.Arg590Gln) results in a conservative amino acid change located in the ABC transporter-like, ATP-binding domain (IPR003439) 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 0.0045 in 251094 control chromosomes in the gnomAD database, including 4 homozygotes. The observed variant frequency is approximately 2.0 fold of the estimated maximal expected allele frequency for a pathogenic variant in ABCB4 causing Familial Intrahepatic Cholestasis phenotype (0.0022), strongly suggesting that the variant is benign. c.1769G>A has been reported in the literature among individuals with ABCB4-related conditions such as Anicteric Cholestasis, low phospholipid-associated cholelithiasis (LPAC), Progressive familial intrahepatic cholestasis (example, Ziol_2008, Tuan Huynh_2019, Colombo_2011, Droge_2017). These data do not allow any conclusion about variant significance. At-least one co-occurrence in cis with another presumably pathogenic variant(s) has been reported (Colombo_2011, ABCB4 c.2284G>T, p.G762X), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (Benign/Likely Benign, n=2; VUS, n=5). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -

Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 Pathogenic:1
Nov 03, 2021
Myriad Genetics, Inc.
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

NM_000404.2(GLB1):c.1769G>A(R590H) is a missense variant classified as likely pathogenic in the context of GLB1-related disorders. R590H has been observed in cases with relevant disease (PMID: 8213816, 27619815, Shekar_2019_(no PMID; poster), 26646981, 33737400). Functional assessments of this variant are available in the literature (PMID: 8213816, 21520340, 23337983). R590H has been observed in population frequency databases (gnomAD: SAS 0.003%). In summary, NM_000404.2(GLB1):c.1769G>A(R590H) is a missense variant that 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 Pathogenic:1
Mar 18, 2024
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.1769G>A (p.Arg590His) results in a non-conservative amino acid change located in the galactose-binding domain (IPR048913) of the encoded protein sequence. Five 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 249130 control chromosomes (gnomAD). c.1769G>A has been reported in the literature in individuals affected with GM1 Gangliosidosis (e.g. Boustany_1993, Regier_2016, Quaio_2020). Publications also reported experimental evidence evaluating an impact on protein function, and demonstrated decreased enzyme activity (e.g. Boustany_1993, Higaki_2011, Takai_2013). ClinVar contains an entry for this variant (Variation ID: 92901). Based on the evidence outlined above, the variant was classified as pathogenic. -

Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 Pathogenic:1
Apr 26, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B Pathogenic:1
Sep 06, 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 histidine, which is basic and polar, at codon 590 of the GLB1 protein (p.Arg590His). This variant is present in population databases (rs398123351, gnomAD 0.003%). This missense change has been observed in individuals with GM1-gangliosidosis (PMID: 8213816, 26646981). ClinVar contains an entry for this variant (Variation ID: 92901). 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: 8213816, 23337983). This variant disrupts the p.Arg590 amino acid residue in GLB1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16941474, 17309651, 23430803). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Infantile GM1 gangliosidosis Pathogenic:1
-
Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.51
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.43
CADD
Pathogenic
33
DANN
Pathogenic
1.0
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
1.0
.;.;D
M_CAP
Pathogenic
0.31
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
1.1
D
PhyloP100
7.8
PrimateAI
Uncertain
0.71
T
PROVEAN
Pathogenic
-4.5
D;D;D
REVEL
Pathogenic
0.91
Sift
Pathogenic
0.0
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Polyphen
1.0
.;.;D
Vest4
0.98
MutPred
0.92
Loss of MoRF binding (P = 0.0426);.;.;
MVP
0.98
MPC
0.97
ClinPred
1.0
D
GERP RS
5.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
gMVP
0.93
Mutation Taster
=2/98
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs398123351; hg19: chr3-33038802; COSMIC: COSV100256995; API