Genetic Variant NM_000046.5:c.1143-1G>T (chr5-78839427-C-A) – ACMG Classification: Pathogenic (12 pts)

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_000046.5(ARSB):c.1143-1G>T variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000685 in 1,460,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ARSB
NM_000046.5 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 4.92

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 7.1, offset of 5, new splice context is: aaaattgttttccattgaAGgaa. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 5-78839427-C-A is Pathogenic according to our data. Variant chr5-78839427-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 2133456.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARSB	NM_000046.5 link	c.1143-1G>T		splice_acceptor_variant, intron_variant	Intron 5 of 7	ENST00000264914.10	NP_000037.2	P15848-1A0A024RAJ9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARSB	ENST00000264914.10 link	c.1143-1G>T		splice_acceptor_variant, intron_variant	Intron 5 of 7	1	NM_000046.5	ENSP00000264914.4		P15848-1
ARSB	ENST00000396151.7 link	c.1143-1G>T		splice_acceptor_variant, intron_variant	Intron 6 of 7	1		ENSP00000379455.3		P15848-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460864

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726766

show subpopulations

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:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 6

Pathogenic:1

May 04, 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. Studies have shown that disruption of this splice site results in skipping of exon 6 and introduces a premature termination codon (PMID: 18406185). The resulting mRNA is expected to undergo nonsense-mediated decay. Disruption of this splice site has been observed in individual(s) with Mucopolysaccharidosis type VI (PMID: 17458871, 32075597). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 5 of the ARSB gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.68

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Uncertain

0.89

GERP RS

5.9

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.91

SpliceAI score (max)

0.89

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.50

Position offset: -6

DS_AL_spliceai

0.89

Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over