Genetic Variant GBA3:p.Thr88Ala (chr4-22736184-A-G) – 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.262A>G(p.Thr88Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000383 in 1,613,426 control chromosomes in the GnomAD database, including 1 homozygotes. 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. T88M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00041 ( 1 hom. )

Consequence

GBA3
ENST00000508166.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.21

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.341A>G	non_coding_transcript_exon_variant	Exon 2 of 5
GBA3	NR_102356.2 link	n.341A>G	non_coding_transcript_exon_variant	Exon 2 of 3
GBA3	NR_102357.2 link	n.263A>G	non_coding_transcript_exon_variant	Exon 2 of 5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	Protein
GBA3	ENST00000508166.5 link	c.262A>G	p.Thr88Ala	missense_variant	Exon 2 of 5	1	ENSP00000427458.1
GBA3	ENST00000503442.1 link	c.262A>G	p.Thr88Ala	missense_variant	Exon 2 of 3	1	ENSP00000422220.1
GBA3	ENST00000511446 link	c.-252A>G		5_prime_UTR_variant	Exon 2 of 5	2	ENSP00000423754.1

Frequencies

GnomAD3 genomes

AF:

0.000158

AC:

AN:

152118

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.000338

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000967

AC:

AN:

248084

Hom.:

AF XY:

0.0000743

AC XY:

AN XY:

134640

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000214

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000406

AC:

594

AN:

1461308

Hom.:

Cov.:

AF XY:

0.000391

AC XY:

284

AN XY:

726938

show subpopulations

Gnomad4 AFR exome

AF:

0.0000598

Gnomad4 AMR exome

AF:

0.00

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:

0.000509

Gnomad4 OTH exome

AF:

0.000431

GnomAD4 genome

AF:

0.000158

AC:

AN:

152118

Hom.:

Cov.:

AF XY:

0.000148

AC XY:

AN XY:

74304

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.000338

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000313

Hom.:

Bravo

AF:

0.000174

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000243

AC:

ExAC

AF:

0.0000662

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 09, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.262A>G (p.T88A) alteration is located in exon 2 (coding exon 2) of the GBA3 gene. This alteration results from a A to G substitution at nucleotide position 262, causing the threonine (T) at amino acid position 88 to be replaced by an alanine (A). 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

Benign

-0.11

BayesDel_noAF

Benign

-0.10

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.28

T;.

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.85

T;T

MetaRNN

Uncertain

0.54

D;D

PrimateAI

Uncertain

0.75

Vest4

0.89

MVP

0.55

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