rs78769774

Variant names:

• chr1-155239933-C-T
• rs78769774
• NM_000157.4:c.260G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000157.4(GBA1):​c.260G>A​(p.Arg87Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,862 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R87W) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: GBA1 NM_000157.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.45
• Publications: 13 publications found

Genes affected

GBA1 (HGNC:4177): (glucosylceramidase beta 1) This gene encodes a lysosomal membrane protein that cleaves the beta-glucosidic linkage of glycosylceramide, an intermediate in glycolipid metabolism. Mutations in this gene cause Gaucher disease, a lysosomal storage disease characterized by an accumulation of glucocerebrosides. A related pseudogene is approximately 12 kb downstream of this gene on chromosome 1. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2010]

GBA1 Gene-Disease associations (from GenCC):

• Parkinson disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• Gaucher disease

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, ClinGen
• Gaucher disease perinatal lethal

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Laboratory for Molecular Medicine, Genomics England PanelApp
• late-onset Parkinson disease

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Gaucher disease type I

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• Gaucher disease type II

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• Gaucher disease type III

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• Gaucher disease-ophthalmoplegia-cardiovascular calcification syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000157.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-155239934-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 4321.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 94 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.1739 (below the threshold of 3.09). Trascript score misZ: 2.2879 (below the threshold of 3.09). GenCC associations: The gene is linked to late-onset Parkinson disease, Gaucher disease perinatal lethal, Gaucher disease, Gaucher disease type I, Gaucher disease-ophthalmoplegia-cardiovascular calcification syndrome, Gaucher disease type II, Parkinson disease, Gaucher disease type III.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.969
• PP5: Variant 1-155239933-C-T is Pathogenic according to our data. Variant chr1-155239933-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 2503944.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
GBA1	NM_000157.4	c.260G>A	p.Arg87Gln	missense_variant	Exon 3 of 11	ENST00000368373.8	NP_000148.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GBA1	ENST00000368373.8	c.260G>A	p.Arg87Gln	missense_variant	Exon 3 of 11	1	NM_000157.4	ENSP00000357357.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461862 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111994

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gaucher disease type I Pathogenic:1

Mar 22, 2024

Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A homozygous missense variant in exon 3 of the GBA1 gene that results in the amino acid substitution of Glutamine for Arginine at codon 87 was detected. The observed variant c.260G>A (p.Arg87Gln) has not been reported in the 1000 genomes and gnomAD databases. The in-silico prediction of the variant is damaging by MutationTaster2 and DANN. In summary, the variant meets our criteria to be classified as pathogenic -

Gaucher disease Pathogenic:1

Feb 10, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GBA1 c.260G>A (p.Arg87Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251272 control chromosomes. c.260G>A has been reported in the literature as a compound heterozygous genotype in individuals affected with Gaucher Disease (example, Erdos_2007, Biegstraaten_2013, Siebert_2013, Kang_2018, Huang_2020, Dimitriou_2020). These data indicate that the variant is likely to be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.259C>T, p.Arg87Trp), supporting the critical relevance of codon 87 to GBA1 protein function. 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: 22350617, 32547927, 17395504, 32165122, 29685539, 16293621, 23430543). ClinVar contains an entry for this variant (Variation ID: 2503944). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.53
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.79	D;D;.
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.3	M;M;M
PhyloP100		6.4
PrimateAI	Uncertain	0.65	T
PROVEAN	Uncertain	-3.6	D;D;D
REVEL	Pathogenic	0.79
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.0070	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.93
MutPred		0.75		Loss of methylation at R87 (P = 0.0505);Loss of methylation at R87 (P = 0.0505);Loss of methylation at R87 (P = 0.0505);
MVP		0.94
MPC		2.0
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.83
gMVP		0.91
Mutation Taster		=6/94	disease causing

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

Other links and lift over

dbSNP: rs78769774; hg19: chr1-155209724;