NM_000404.4:c.1498A>T

Variant names:

• chr3-33014292-T-A
• rs72555368
• NM_000404.4:c.1498A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP5_Moderate

The NM_000404.4(GLB1):​c.1498A>T​(p.Thr500Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T500A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GLB1 NM_000404.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.84
• Publications: 0 publications found

Genes affected

GLB1 (HGNC:4298): (galactosidase beta 1) This gene encodes a member of the glycosyl hydrolase 35 family of proteins. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the mature lysosomal enzyme. This enzyme catalyzes the hydrolysis of a terminal beta-linked galactose residue from ganglioside substrates and other glycoconjugates. Mutations in this gene may result in GM1-gangliosidosis and Morquio B syndrome. [provided by RefSeq, Nov 2015]

GLB1 Gene-Disease associations (from GenCC):

• GM1 gangliosidosis

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
• GM1 gangliosidosis type 3

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• mucopolysaccharidosis type 4B

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• GM1 gangliosidosis type 1

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• GM1 gangliosidosis type 2

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 7 uncertain in NM_000404.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-33014292-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 942.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 110 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: 0.79419 (below the threshold of 3.09). Trascript score misZ: 1.1264 (below the threshold of 3.09). GenCC associations: The gene is linked to mucopolysaccharidosis type 4B, GM1 gangliosidosis, GM1 gangliosidosis type 2, GM1 gangliosidosis type 3, GM1 gangliosidosis type 1.
• PP5: Variant 3-33014292-T-A is Pathogenic according to our data. Variant chr3-33014292-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2052783.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000404.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLB1	NM_000404.4	MANE Select	c.1498A>T	p.Thr500Ser	missense	Exon 15 of 16	NP_000395.3
	GLB1	NM_001317040.2		c.1642A>T	p.Thr548Ser	missense	Exon 16 of 17	NP_001303969.2
	GLB1	NM_001079811.3		c.1408A>T	p.Thr470Ser	missense	Exon 15 of 16	NP_001073279.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLB1	ENST00000307363.10	TSL:1 MANE Select	c.1498A>T	p.Thr500Ser	missense	Exon 15 of 16	ENSP00000306920.4	P16278
	GLB1	ENST00000307377.12	TSL:1	c.1105A>T	p.Thr369Ser	missense	Exon 12 of 13	ENSP00000305920.8	E7EQ29
	GLB1	ENST00000399402.7	TSL:2	c.1408A>T	p.Thr470Ser	missense	Exon 15 of 16	ENSP00000382333.2	P16278

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Benign	22
DANN	Uncertain	0.99
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.76	T
M_CAP	Uncertain	0.093	D
MetaRNN	Uncertain	0.43	T
MetaSVM	Uncertain	0.30	D
PhyloP100		5.8
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-2.6	D
REVEL	Pathogenic	0.67
Sift	Benign	0.25	T
Sift4G	Benign	0.33	T
Polyphen		0.54	P
Vest4		0.14
MutPred		0.55		Loss of loop (P = 0.0374)
MVP		0.94
MPC		0.40
ClinPred		0.96	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.72
Mutation Taster		=42/58	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs72555368; hg19: chr3-33055784;