rs72555372

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000404.4(GLB1):​c.1051C>T​(p.Arg351*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000116 in 1,460,972 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GLB1
NM_000404.4 stop_gained

Scores

2
3
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 1.99

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-33046137-G-A is Pathogenic according to our data. Variant chr3-33046137-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 941.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.1051C>T p.Arg351* stop_gained Exon 10 of 16 ENST00000307363.10 NP_000395.3 P16278

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GLB1ENST00000307363.10 linkc.1051C>T p.Arg351* stop_gained Exon 10 of 16 1 NM_000404.4 ENSP00000306920.4 P16278

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.0000120
AC:
3
AN:
249506
AF XY:
0.0000148
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:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000116
AC:
17
AN:
1460972
Hom.:
0
Cov.:
31
AF XY:
0.0000110
AC XY:
8
AN XY:
726834
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.0000224
AC:
1
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86206
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53394
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5202
European-Non Finnish (NFE)
AF:
0.0000117
AC:
13
AN:
1111890
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60294
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.451
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
Cov.:
31
Alfa
AF:
0.0000401
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-IV-B Pathogenic:2
Nov 16, 2017
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: The GLB1 c.1051C>T (p.Arg351X) variant results in a premature termination codon, predicted to cause a truncated or absent GLB1 protein due to nonsense mediated decay, which are commonly known mechanisms for disease. This variant was found in 3/246162 control chromosomes at a frequency of 0.0000122, which does not exceed the estimated maximal expected allele frequency of a pathogenic GLB1 variant (0.0020412). The c.1051C>T has been reported in at least four affected, with residual GLB1 activity in their fibroblasts being less than 2% of normal via publications. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

May 03, 2020
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 Pathogenic:2
Feb 14, 2017
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Feb 12, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Infantile GM1 gangliosidosis Pathogenic:2
Nov 10, 2020
Genetics and Genomic Medicine Centre, NeuroGen Healthcare, NeuroGen Healthcare
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Oct 09, 2020
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -

Spastic ataxia Pathogenic:1
Jan 04, 2021
Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

not provided Pathogenic:1
Oct 23, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in unrelated individuals with GM1-gangliosidosis in the published literature who were homozygous for this variant or harbored a second variant in GLB1 (PMID: 10841810, 15714521, 33240792); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 21497194, 8922281, 25600812, 31367523, 25525159, 33737400, 15714521, 22784478, 34445196, 33859490, 33240792, 10841810) -

GM1-gangliosidosis, type I, with cardiac involvement Pathogenic:1
May 14, 2019
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B Pathogenic:1
Jan 18, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg351*) in the GLB1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GLB1 are known to be pathogenic (PMID: 18524657). This variant is present in population databases (rs72555372, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with GM1-gangliosidosis (PMID: 10841810, 15714521). ClinVar contains an entry for this variant (Variation ID: 941). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
39
DANN
Uncertain
1.0
Eigen
Uncertain
0.44
Eigen_PC
Benign
0.21
FATHMM_MKL
Uncertain
0.92
D
PhyloP100
2.0
Vest4
0.97
GERP RS
4.2
Mutation Taster
=1/199
disease causing (ClinVar)

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: rs72555372; hg19: chr3-33087629; API