rs398123357

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_000404.4(GLB1):​c.734-8A>G variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,613,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

GLB1
NM_000404.4 splice_region, splice_polypyrimidine_tract, intron

Scores

2
Splicing: ADA: 0.9976
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3O:1

Conservation

PhyloP100: 0.960
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
GLB1NM_000404.4 linkuse as main transcriptc.734-8A>G splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant ENST00000307363.10

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
GLB1ENST00000307363.10 linkuse as main transcriptc.734-8A>G splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant 1 NM_000404.4 P2

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152080
Hom.:
0
Cov.:
32
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000802
AC:
2
AN:
249454
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135330
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 SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461854
Hom.:
0
Cov.:
31
AF XY:
0.0000110
AC XY:
8
AN XY:
727234
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000989
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
152080
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74284
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000658
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 29, 2023Variant summary: GLB1 c.734-8A>G alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: One predict the variant abolishes a 3' acceptor site. Two predict the variant weakens a 3' acceptor site. Four predict the variant creates a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8e-06 in 249454 control chromosomes. c.734-8A>G has been reported in the literature in individuals affected with Mucopolysaccharidosis Type IVB (Morquio Syndrome B) and Gangliosidosis (Uttarilli_2019, Hofer_2010). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 35614200, 20175788, 30408610). One submitter has cited clinical-significance assessments for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)May 19, 2014- -
Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingCounsylSep 12, 2017- -
GM1 gangliosidosis Other:1
not provided, no classification providedphenotyping onlyGenomeConnect - GM1-Variant classified as Likely pathogenic and reported on 12-08-2021 by Lab or GTR ID 500188. GenomeConnect-GM1 assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.83
CADD
Uncertain
23
DANN
Benign
0.56

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
1.0
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_AG_spliceai
1.0
Position offset: -1
DS_AL_spliceai
0.97
Position offset: -8

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs398123357; hg19: chr3-33095049; API