rs968221254

Variant names:

• chr3-33016736-G-C
• rs968221254
• NM_000404.4:c.1452C>G

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000404.4(GLB1):​c.1452C>G​(p.Asn484Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000103 in 1,461,796 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N484S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000010 (0 hom.)
• Consequence: GLB1 NM_000404.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 3.04
• Publications: 4 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: Myriad Women’s Health, ClinGen
• GM1 gangliosidosis type 3

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

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

ACMG classification

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000404.4
• PM2: Very rare variant in population databases, with high coverage
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986
• PP5: Variant 3-33016736-G-C is Pathogenic according to our data. Variant chr3-33016736-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 553506.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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.1452C>G	p.Asn484Lys	missense	Exon 14 of 16	NP_000395.3
	GLB1	NM_001317040.2		c.1596C>G	p.Asn532Lys	missense	Exon 15 of 17	NP_001303969.2
	GLB1	NM_001079811.3		c.1362C>G	p.Asn454Lys	missense	Exon 14 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.1452C>G	p.Asn484Lys	missense	Exon 14 of 16	ENSP00000306920.4
	GLB1	ENST00000307377.12	TSL:1	c.1059C>G	p.Asn353Lys	missense	Exon 11 of 13	ENSP00000305920.8
	GLB1	ENST00000399402.7	TSL:2	c.1362C>G	p.Asn454Lys	missense	Exon 14 of 16	ENSP00000382333.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000103 AC: 15 AN: 1461796 Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7 AN XY: 727198

African (AFR) AF: 0.0000299 AC: 1 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

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

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1111950

Other (OTH) AF: 0.0000497 AC: 3 AN: 60386

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	1	-	Mucopolysaccharidosis, MPS-IV-B;C0268271:Infantile GM1 gangliosidosis;C0268272:GM1 gangliosidosis type 2;C0268273:GM1 gangliosidosis type 3 (2)
1	-	-	GM1 gangliosidosis;C0086652:Mucopolysaccharidosis, MPS-IV-B (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	26
DANN	Uncertain	1.0
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
PhyloP100		3.0
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.79
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.0060	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.93		Gain of methylation at N484 (P = 0.0224)
MVP		0.99
MPC		0.93
ClinPred		0.99	D
GERP RS		6.0
gMVP		0.98
Mutation Taster		=0/100	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: rs968221254; hg19: chr3-33058228;