Genetic Variant GLB1:p.Leu305Phe (chr3-33051798-C-G) – ACMG Classification: Uncertain_significance (1 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_000404.4(GLB1):c.915G>C(p.Leu305Phe) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000684 in 1,461,894 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 predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

GLB1
NM_000404.4 missense, splice_region

Scores

Splicing: ADA: 0.8273

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.78

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 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.40172622).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GLB1	NM_000404.4 link	c.915G>C	p.Leu305Phe	missense_variant, splice_region_variant	Exon 9 of 16	ENST00000307363.10	NP_000395.3	P16278

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GLB1	ENST00000307363.10 link	c.915G>C	p.Leu305Phe	missense_variant, splice_region_variant	Exon 9 of 16	1	NM_000404.4	ENSP00000306920.4		P16278

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000361

AC:

AN:

249300

Hom.:

AF XY:

0.0000370

AC XY:

AN XY:

135252

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000232

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000885

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461894

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000134

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000434

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000497

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B

Uncertain:1

Aug 22, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 305 of the GLB1 protein (p.Leu305Phe). This variant is present in population databases (rs772986593, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GLB1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

0.17

BayesDel_addAF

Benign

-0.084

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.56

.;.;.;D

Eigen

Benign

0.12

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.85

.;.;T;D

MetaRNN

Benign

0.40

T;T;T;T

MetaSVM

Pathogenic

0.87

PrimateAI

Benign

0.40

PROVEAN

Uncertain

-2.4

N;D;N;D

REVEL

Uncertain

0.50

Sift

Benign

0.40

T;T;T;T

Sift4G

Benign

0.64

T;T;T;T

Polyphen

0.96

.;.;D;.

Vest4

0.50

MutPred

0.77

Loss of stability (P = 0.1463);.;.;.;

MVP

0.98

MPC

0.84

ClinPred

0.12

GERP RS

5.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

gMVP

0.76

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.83

dbscSNV1_RF

Benign

0.56

SpliceAI score (max)

0.20

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.20

Position offset: 0

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over