rs1557340233

chrX-149503341-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000202.8(IDS):c.389C>T(p.Thr130Ile) 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T130A) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 23)
• Consequence: IDS NM_000202.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.42

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000202.8
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IDS	NM_000202.8	c.389C>T	p.Thr130Ile	missense_variant	3/9	ENST00000340855.11
IDS	NM_001166550.4	c.119C>T	p.Thr40Ile	missense_variant	3/9
IDS	NM_006123.5	c.389C>T	p.Thr130Ile	missense_variant	3/8
IDS	NR_104128.2	n.558C>T		non_coding_transcript_exon_variant	3/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IDS	ENST00000340855.11	c.389C>T	p.Thr130Ile	missense_variant	3/9	1	NM_000202.8	P1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis, MPS-II Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 13, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been reported in an individual affected with mucopolysaccharidosis type II (PMID: 21829674). This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with isoleucine at codon 130 of the IDS protein (p.Thr130Ile). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and isoleucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.81
Cadd	Pathogenic	29
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;.;D
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Pathogenic	4.0	H;H;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-5.2	D;D;D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0030	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.95
MutPred		0.83		Loss of glycosylation at T130 (P = 0.0744);Loss of glycosylation at T130 (P = 0.0744);Loss of glycosylation at T130 (P = 0.0744);
MVP		1.0
MPC		2.3
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.98
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		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: rs1557340233; hg19: chrX-148584871;