chr1-155235790-C-A

Position:

• chr1-155235790-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000157.4(GBA1):​c.1279G>T​(p.Glu427*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. E427E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 30)
• Consequence: GBA1 NM_000157.4 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.69

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-155235790-C-A is Pathogenic according to our data. Variant chr1-155235790-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 505377.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GBA1	NM_000157.4	c.1279G>T	p.Glu427*	stop_gained	9/11	ENST00000368373.8	NP_000148.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GBA1	ENST00000368373.8	c.1279G>T	p.Glu427*	stop_gained	9/11	1	NM_000157.4	ENSP00000357357.3

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 30

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Gaucher disease Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Nov 21, 2016

The p.Glu427X variant in GBA has not been previously reported in patients with G aucher disease and was absent from large population studies. This nonsense varia nt leads to a premature termination codon at position 427, which is predicted to lead to a truncated or absent protein. Biallelic mutations (including loss of f unction) in the GBA gene cause Gaucher disease. In summary, this variant meets c riteria to be classified as likely pathogenic for Gaucher disease in an autosoma l recessive manner based upon predicted null effect. Please note that, due to th e technical limitations of the next generation sequencing and Sanger confirmatio n assays, the GBA pseudogene cannot be reliably avoided. Therefore, before makin g clinical decisions regarding this variant, further testing via targeted assays that guarantee avoidance of GBA pseudogene would be required to confirm the pre sence of this variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.95	D
Vest4		0.87
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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

Other links and lift over

dbSNP: rs149171124; hg19: chr1-155205581;