rs774358117

Variant names:

• chr5-78780506-A-G
• rs774358117
• NM_000046.5:c.1493T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000046.5(ARSB):​c.1493T>C​(p.Leu498Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,876 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: ARSB NM_000046.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 7.85

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 5-78780506-A-G is Pathogenic according to our data. Variant chr5-78780506-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 559717.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARSB	NM_000046.5	c.1493T>C	p.Leu498Pro	missense_variant	Exon 8 of 8	ENST00000264914.10	NP_000037.2
ARSB	XM_011543390.2	c.1493T>C	p.Leu498Pro	missense_variant	Exon 9 of 9		XP_011541692.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARSB	ENST00000264914.10	c.1493T>C	p.Leu498Pro	missense_variant	Exon 8 of 8	1	NM_000046.5	ENSP00000264914.4
ARSB	ENST00000521011.1	n.458T>C		non_coding_transcript_exon_variant	Exon 3 of 3	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727238

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mucopolysaccharidosis type 6 Pathogenic:3 Uncertain:1

Apr 20, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 13, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 01, 2018

Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

In vitro functional studies supportive of a damaging effect on the gene product (low to no ARSB activity in homozygotes; PS3); Very low frequency in ExAC (PM2) -

Jun 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 498 of the ARSB protein (p.Leu498Pro). This variant is present in population databases (rs774358117, gnomAD 0.0009%). This missense change has been observed in individual(s) with mucopolysaccharidosis type VI (PMID: 8651289). ClinVar contains an entry for this variant (Variation ID: 559717). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ARSB protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ARSB function (PMID: 8651289). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.86	D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.2	D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.93		Gain of disorder (P = 0.0221);
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.96
gMVP		0.99

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: rs774358117; hg19: chr5-78076329;