rs757061042

Positions:

• chr5-78969067-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000046.5(ARSB):​c.438G>A​(p.Trp146*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,884 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 (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ARSB NM_000046.5 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.82

Genes affected

ARSB (HGNC:714): (arylsulfatase B) Arylsulfatase B encoded by this gene belongs to the sulfatase family. The arylsulfatase B homodimer hydrolyzes sulfate groups of N-Acetyl-D-galactosamine, chondriotin sulfate, and dermatan sulfate. The protein is targeted to the lysozyme. Mucopolysaccharidosis type VI is an autosomal recessive lysosomal storage disorder resulting from a deficiency of arylsulfatase B. Two alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Dec 2016]

ARSB (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 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 5-78969067-C-T is Pathogenic according to our data. Variant chr5-78969067-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 559787.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARSB	NM_000046.5	c.438G>A	p.Trp146*	stop_gained	2/8	ENST00000264914.10	NP_000037.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARSB	ENST00000264914.10	c.438G>A	p.Trp146*	stop_gained	2/8	1	NM_000046.5	ENSP00000264914.4
ARSB	ENST00000396151.7	c.438G>A	p.Trp146*	stop_gained	3/8	1		ENSP00000379455.3
ARSB	ENST00000565165.2	c.438G>A	p.Trp146*	stop_gained	2/5	1		ENSP00000456339.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251470 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135908

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000936 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis type 6 Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 07, 2022	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 559787). This premature translational stop signal has been observed in individual(s) with mucopolysaccharidosis type VI (PMID: 17458871). This variant is present in population databases (rs757061042, gnomAD 0.0009%). This sequence change creates a premature translational stop signal (p.Trp146*) in the ARSB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ARSB are known to be pathogenic (PMID: 17458871, 22133300). -
Likely pathogenic, criteria provided, single submitter	curation	Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova	Jan 01, 2018	Nonsense variant (PVS1); Very low frequency in ExAc (PM2) -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 14, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 12, 2020	Variant summary: ARSB c.438G>A (p.Trp146X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-06 in 251470 control chromosomes. c.438G>A has been reported in the literature in individuals affected with Mucopolysaccharidosis Type VI (Maroteaux-Lamy Syndrome) (example, Karageorgos_2007, Thumler_2012, Tomanin_2018). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.68	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	46
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.98
GERP RS		6.1

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

Publications

LitVar

Other links and lift over

dbSNP: rs757061042; hg19: chr5-78264890;