Genetic Variant GBA3:p.Thr88Met (chr4-22736185-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The ENST00000508166.5(GBA3):c.263C>T(p.Thr88Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,613,386 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T88A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GBA3
ENST00000508166.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.91

Variant links:

Genes affected

GBA3 (HGNC:19069): (glucosylceramidase beta 3 (gene/pseudogene)) The protein encoded by this gene is a cytosolic enzyme that can hydrolyze several types of glycosides. The enzyme has its highest activity at neutral pH and is predominantly expressed in human liver, kidney, intestine, and spleen. This gene is a polymorphic pseudogene, with the most common allele being the functional allele that encodes the full-length protein. Some individuals contain a single nucleotide polymorphism that results in a premature stop codon in the coding region, and therefore this allele is pseudogenic due to the failure to produce a functional full-length protein. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Apr 2022]

GBA3 links:

LOC105374521 (HGNC:):

LOC105374521 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank
GBA3	NR_102355.2 link	n.342C>T	non_coding_transcript_exon_variant	Exon 2 of 5
GBA3	NR_102356.2 link	n.342C>T	non_coding_transcript_exon_variant	Exon 2 of 3
GBA3	NR_102357.2 link	n.264C>T	non_coding_transcript_exon_variant	Exon 2 of 5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	Protein
GBA3	ENST00000508166.5 link	c.263C>T	p.Thr88Met	missense_variant	Exon 2 of 5	1	ENSP00000427458.1
GBA3	ENST00000503442.1 link	c.263C>T	p.Thr88Met	missense_variant	Exon 2 of 3	1	ENSP00000422220.1
GBA3	ENST00000511446 link	c.-251C>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 5	2	ENSP00000423754.1
GBA3	ENST00000511446 link	c.-251C>T		5_prime_UTR_variant	Exon 2 of 5	2	ENSP00000423754.1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152084

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000121

AC:

AN:

248024

Hom.:

AF XY:

0.00000743

AC XY:

AN XY:

134616

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461302

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

726946

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152084

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74282

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000658

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Sep 14, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.263C>T (p.T88M) alteration is located in exon 2 (coding exon 2) of the GBA3 gene. This alteration results from a C to T substitution at nucleotide position 263, causing the threonine (T) at amino acid position 88 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Uncertain

0.092

BayesDel_noAF

Uncertain

-0.020

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

T;.

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

D;D

MetaRNN

Uncertain

0.58

D;D

PrimateAI

Uncertain

0.78

Vest4

0.78

MVP

0.54

GERP RS

5.8

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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