rs77959976

Variant names:

• chr1-155238619-C-T
• rs77959976
• NM_000157.4:c.486G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_000157.4(GBA1):​c.486G>A​(p.Met162Ile) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M162V) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 29)
• Consequence: GBA1 NM_000157.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.95
• Publications: 1 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: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 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 chr1-155238621-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1704378.
• 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, 0.752

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GBA1	NM_000157.4	c.486G>A	p.Met162Ile	missense_variant	Exon 5 of 11	ENST00000368373.8	NP_000148.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GBA1	ENST00000368373.8	c.486G>A	p.Met162Ile	missense_variant	Exon 5 of 11	1	NM_000157.4	ENSP00000357357.3

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 29

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Benign	23
DANN	Benign	0.85
DEOGEN2	Uncertain	0.67	D;D;.;.
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.18
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.95	.;D;D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.75	D;D;D;D
MetaSVM	Uncertain	0.52	D
MutationAssessor	Benign	0.10	N;N;.;.
PhyloP100		7.0
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-0.66	N;N;N;N
REVEL	Pathogenic	0.66
Sift	Benign	0.73	T;T;T;T
Sift4G	Benign	1.0	T;T;T;T
Polyphen		0.23	B;B;.;.
Vest4		0.85
MutPred		0.59		Loss of methylation at R159 (P = 0.1201);Loss of methylation at R159 (P = 0.1201);.;.;
MVP		0.88
MPC		1.0
ClinPred		0.68	D
GERP RS		3.5
Varity_R		0.59
gMVP		0.84
Mutation Taster		=34/66	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: rs77959976; hg19: chr1-155208410;