5-78885803-C-T

Position:

• chr5-78885803-C-T

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.923G>A​(p.Gly308Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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)
• Consequence: ARSB NM_000046.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 7.86

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, 0.971
• PP5: Variant 5-78885803-C-T is Pathogenic according to our data. Variant chr5-78885803-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 559825.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARSB	NM_000046.5	c.923G>A	p.Gly308Glu	missense_variant	5/8	ENST00000264914.10	NP_000037.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARSB	ENST00000264914.10	c.923G>A	p.Gly308Glu	missense_variant	5/8	1	NM_000046.5	ENSP00000264914	P1
ARSB	ENST00000396151.7	c.923G>A	p.Gly308Glu	missense_variant	6/8	1		ENSP00000379455
ARSB	ENST00000565165.2	c.923G>A	p.Gly308Glu	missense_variant	5/5	1		ENSP00000456339
ARSB	ENST00000521800.2	n.105G>A		non_coding_transcript_exon_variant	2/3	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mucopolysaccharidosis type 6 Pathogenic:2 Uncertain:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 20, 2023	For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Gly308 amino acid residue in ARSB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17643332, 18406185). 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. ClinVar contains an entry for this variant (Variation ID: 559825). This missense change has been observed in individual(s) with clinical features of mucopolysaccharidosis type VI (PMID: 24798265). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 308 of the ARSB protein (p.Gly308Glu). -
Uncertain significance, criteria provided, single submitter	curation	Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova	Jan 01, 2018	Absent from GnomAD (PM2) -
Likely pathogenic, criteria provided, single submitter	clinical testing	Breakthrough Genomics, Breakthrough Genomics	Sep 09, 2020	This variant was previously reported in compound heterozygous state in a 4years old Syrian patient diagnosed with Mucopolysaccharidosis type VI and it was reported in the literature that this patient showed arylsulphatase B activities far below the reference range and b-galactosidase activity within normal limits, compatible with MPS VI [PMID: 24798265] . In addition, several other exon 5 missense variants p.(Gly303Glu) and p.(Pro313Ala) in the vicinity of identified variant have been previously reported in multiple MPS VI patients and was classified as ‘likely pathogenic’ [PMID: 30118150]. -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 02, 2023	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.97	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.5	M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-6.3	D;D;D
REVEL	Pathogenic	0.99
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.029	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.95
MutPred		0.83		Loss of catalytic residue at A307 (P = 0.0243);Loss of catalytic residue at A307 (P = 0.0243);Loss of catalytic residue at A307 (P = 0.0243);
MVP		0.99
MPC		1.0
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.97
gMVP		0.93

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: rs1554079333; hg19: chr5-78181626;