X-149498308-C-G

Position:

• chrX-149498308-C-G

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The ENST00000340855.11(IDS):​c.508-1G>C variant causes a splice acceptor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: IDS ENST00000340855.11 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.54

Genes affected

IDS (HGNC:5389): (iduronate 2-sulfatase) This gene encodes a member of the sulfatase family of proteins. The encoded preproprotein is proteolytically processed to generate two polypeptide chains. This enzyme is involved in the lysosomal degradation of heparan sulfate and dermatan sulfate. Mutations in this gene are associated with the X-linked lysosomal storage disease mucopolysaccharidosis type II, also known as Hunter syndrome. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.12099214 fraction of the gene. Cryptic splice site detected, with MaxEntScore 2.8, offset of -28, new splice context is: catttcttgcacttaaaaAGctg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-149498308-C-G is Pathogenic according to our data. Variant chrX-149498308-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 221977.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-149498308-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IDS	NM_000202.8	c.508-1G>C		splice_acceptor_variant		ENST00000340855.11	NP_000193.1
IDS	NM_001166550.4	c.238-1G>C		splice_acceptor_variant			NP_001160022.1
IDS	NM_006123.5	c.508-1G>C		splice_acceptor_variant			NP_006114.1
IDS	NR_104128.2	n.677-1G>C		splice_acceptor_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IDS	ENST00000340855.11	c.508-1G>C		splice_acceptor_variant		1	NM_000202.8	ENSP00000339801	P1

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mucopolysaccharidosis, MPS-II Pathogenic:2

Pathogenic, criteria provided, single submitter	literature only	Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova	Jun 07, 2024	Null variant (PVS1_Strong), Absent from controls (or at low frequency) in gnomAD database (PM2_Moderate), Patient’s phenotype or family history highly specific for the disease (PP4_Strong) -
Pathogenic, criteria provided, single submitter	research	MOLECULAR BIOLOGY LABORATORY, INSTITUTO NACIONAL DE PEDIATRIA	Oct 18, 2015	Pathogenic variation identified in a Hunter syndrome male patient with I2S deficiency. He presents mental retardation, but no seizures, nor hydrocephaly. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	29
DANN	Uncertain	0.99
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.97
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.40		Position offset: -17
DS_AL_spliceai		0.97		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs113993947; hg19: chrX-148579839;