rs72555369

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PM5PP2

The NM_000404.4(GLB1):​c.1223A>G​(p.Gln408Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,554 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q408P) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense

Scores

2
7
8

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.31

Publications

6 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: Uncertain_significance. The variant received 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-33021576-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 943.Status of the report is no_assertion_criteria_provided, 0 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.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GLB1NM_000404.4 linkc.1223A>G p.Gln408Arg missense_variant Exon 12 of 16 ENST00000307363.10 NP_000395.3 P16278

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLB1ENST00000307363.10 linkc.1223A>G p.Gln408Arg missense_variant Exon 12 of 16 1 NM_000404.4 ENSP00000306920.4 P16278

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461554
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727040
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44674
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26106
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86150
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111902
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jul 01, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B Uncertain:1
Apr 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 408 of the GLB1 protein (p.Gln408Arg). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. This variant has not been reported in the literature in individuals affected with GLB1-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.098
BayesDel_addAF
Pathogenic
0.22
D
BayesDel_noAF
Uncertain
0.080
CADD
Uncertain
25
DANN
Uncertain
1.0
Eigen
Uncertain
0.25
Eigen_PC
Uncertain
0.35
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Benign
0.64
.;.;T
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.35
T;T;T
MetaSVM
Uncertain
0.79
D
PhyloP100
6.3
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-2.0
N;N;N
REVEL
Uncertain
0.58
Sift
Benign
0.072
T;T;T
Sift4G
Benign
0.47
T;T;T
Polyphen
0.73
.;.;P
Vest4
0.44
MutPred
0.62
Gain of sheet (P = 0.0827);.;.;
MVP
0.94
MPC
0.53
ClinPred
0.96
D
GERP RS
5.3
gMVP
0.76
Mutation Taster
=79/21
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.28
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.28
Position offset: -24

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

Publications

Other links and lift over

dbSNP: rs72555369; hg19: chr3-33063068; API