5-78781863-G-C

Variant names:

• chr5-78781863-G-C
• rs1057520739
• NM_000046.5:c.1325C>G

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000046.5(ARSB):​c.1325C>G​(p.Thr442Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,774 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. T442M) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ARSB NM_000046.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.32
• Publications: 3 publications found

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 Gene-Disease associations (from GenCC):

• mucopolysaccharidosis type 6

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Genomics England PanelApp, Illumina, Labcorp Genetics (formerly Invitae), G2P, ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000046.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr5-78781863-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 379809.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 85 curated pathogenic missense variants (we use a threshold of 10). The gene has 14 curated benign missense variants. Gene score misZ: 0.63089 (below the threshold of 3.09). Trascript score misZ: -0.06109 (below the threshold of 3.09). GenCC associations: The gene is linked to mucopolysaccharidosis type 6.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97
• PP5: Variant 5-78781863-G-C is Pathogenic according to our data. Variant chr5-78781863-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 2203661.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000046.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARSB	NM_000046.5	MANE Select	c.1325C>G	p.Thr442Arg	missense	Exon 7 of 8	NP_000037.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ARSB	ENST00000264914.10	TSL:1 MANE Select	c.1325C>G	p.Thr442Arg	missense	Exon 7 of 8	ENSP00000264914.4
	ARSB	ENST00000521011.1	TSL:3	n.290C>G		non_coding_transcript_exon	Exon 2 of 3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461774 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727192

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111922

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis type 6 Pathogenic:3

Apr 11, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 12, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: ARSB c.1325C>G (p.Thr442Arg) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. A different variant, c.1325C>T (p.Thr442Met) has been reported as pathogenic/likely pathogenic, supporting the critical relevance of the Thr442 residue to ARSB protein function. The variant was absent in 251396 control chromosomes. c.1325C>G has been reported in the literature in at-least one individual affected with Mucopolysaccharidosis Type VI (Maroteaux-Lamy Syndrome) (example Karageorgos_2007). At least one publication reports experimental evidence evaluating an impact on protein function (Karageorgos_2007). The most pronounced variant effect results in <3% of normal activity in the fibroblast cell line from a patient with this variant in compound heterozygosity with a null variant. The following publications have been ascertained in the context of this evaluation (PMID: 17458871, 18248830, 25190157). ClinVar contains an entry for this variant (Variation ID: 2203661). Based on the evidence outlined above, the variant was classified as pathogenic.

Dec 21, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Thr442 amino acid residue in ARSB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17458871, 25190157; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. This missense change has been observed in individual(s) with mucopolysaccharidosis type VI (PMID: 17458871). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 442 of the ARSB protein (p.Thr442Arg).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	D
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.71	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		8.3
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-5.5	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0060	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.87		Gain of MoRF binding (P = 0.0079)
MVP		0.99
MPC		0.93
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.95
gMVP		0.91
Mutation Taster		=12/88	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: rs1057520739; hg19: chr5-78077686;