3-32997049-A-C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM2PP2BP4_Strong

The NM_000404.4(GLB1):​c.2030T>G​(p.Val677Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,613,940 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. V677V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

3
14

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: -0.567

Publications

1 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: Likely_benign. The variant received -1 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.
BP4
Computational evidence support a benign effect (MetaRNN=0.05303365).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLB1NM_000404.4 linkc.2030T>G p.Val677Gly missense_variant Exon 16 of 16 ENST00000307363.10 NP_000395.3 P16278

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLB1ENST00000307363.10 linkc.2030T>G p.Val677Gly missense_variant Exon 16 of 16 1 NM_000404.4 ENSP00000306920.4 P16278
GLB1ENST00000307377.12 linkc.1637T>G p.Val546Gly missense_variant Exon 13 of 13 1 ENSP00000305920.8 E7EQ29
GLB1ENST00000399402.7 linkc.1940T>G p.Val647Gly missense_variant Exon 16 of 16 2 ENSP00000382333.2 P16278

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152058
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.00000802
AC:
2
AN:
249468
AF XY:
0.00000739
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000889
AC:
13
AN:
1461882
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000809
AC:
9
AN:
1112004
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000197
AC:
3
AN:
152058
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74270
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41386
American (AMR)
AF:
0.000131
AC:
2
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10582
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-B Pathogenic:1
May 12, 2021
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B Uncertain:1
Oct 26, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 677 of the GLB1 protein (p.Val677Gly). This variant is present in population databases (rs767685019, gnomAD 0.003%). This missense change has been observed in individual(s) with GLB1-related conditions (PMID: 33558080; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 968996). 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 not expected to disrupt GLB1 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.083
BayesDel_addAF
Benign
-0.047
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
0.92
DANN
Benign
0.96
Eigen
Benign
-1.6
Eigen_PC
Benign
-1.7
FATHMM_MKL
Benign
0.029
N
LIST_S2
Benign
0.29
.;.;T
M_CAP
Benign
0.083
D
MetaRNN
Benign
0.053
T;T;T
MetaSVM
Uncertain
-0.21
T
PhyloP100
-0.57
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-0.68
N;N;N
REVEL
Benign
0.18
Sift
Uncertain
0.0050
D;D;D
Sift4G
Uncertain
0.0070
D;D;D
Polyphen
0.0
.;.;B
Vest4
0.047
MutPred
0.26
Loss of stability (P = 0);.;.;
MVP
0.30
MPC
0.31
ClinPred
0.047
T
GERP RS
-8.0
gMVP
0.64
Mutation Taster
=100/0
polymorphism

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

Other links and lift over

dbSNP: rs767685019; hg19: chr3-33038541; API