rs772416503

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PS3_SupportingPP4_ModeratePM2_SupportingPP3PM3_Strong

This summary comes from the ClinGen Evidence Repository: The NM_000203.5:c.1487C>G variant in IDUA is a missense variant predicted to cause substitution of Proline by Arginine at amino acid 496 p.(Pro496Arg). At least 8 patients are compound heterozygous for the variant and another variant in IDUA that has been classified as pathogenic or likely pathogenic by the ClinGen LD VCEP including c.793G>C (p.Gly265Arg) (ClinVar Variation ID: 638074) (PMID:21394825, LP, 0.25), c.152G>A (p.Gly51Asp) (ClinVar Variation ID: 193061) (PMID:21394825, P, 2 x 0.5), c.208C>T (p.Gln70Ter) (ClinVar Variation ID: 11909) (PMID:21394825, P, 4 patients, max 2 x 0.5), and c.1598C>G (p.Pro533Arg) (PMID:34408967, P, 0.5 points). One individual is homozygous for the variant (PMID:34408967, 0.5 points). This variant has also been reported in compound heterozygosity with p.Arg89Trp (PMID:21394825), c.1727+1G>A (PMID:21394825), c.1854C>A (p.Tyr618Ter) (PMID:27520059) and c.878_889dup (PMID 28752568). The allelic data from these patients will be used in the subsequent classification of then second variant and is not included here to avoid circular logic. Total 3.25 points (PM3_Strong). In one report (PMID:27520059), there was evidence of decreased IDUA enzyme activity, increased urine glycosaminoglycans and a specific clinical phenotype, allowing for application of PP4_Moderate. The highest population minor allele frequency in gnomAD v4.1.0. is 0.000003515 (4/1137936 alleles) in the European (non-Finnish) population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.00025), meeting this criterion (PM2_Supporting). and has some experimental evidence suggesting absence of IDUA activity when the variant is expressed in Cos-7 cells (PMID:11735025) (PS3_Supporting). Computational predictor tools (REVEL score 0.72) suggest that this variant may be deleterious to IDUA function (PP3). A different missense variant, c.1487C>G (p.Pro496Leu) [ClinVar Variation ID 551675] in the same codon has been classified as likely pathogenic for MPS I by the ClinGen VCEP, however PM5 was not assigned to avoid circular logic. There is a ClinVar entry for this variant (Variation ID: 496861). In summary, this variant meets the criteria to be classified as likely pathogenic for MPS I based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel: PM3_Strong, PP4_Moderate. PS3_Supporting, PM2_Supporting, PP3.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA2802275/MONDO:0001586/091

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000022 ( 0 hom. )

Consequence

IDUA
NM_000203.5 missense

Scores

11
7
1

Clinical Significance

Likely pathogenic reviewed by expert panel P:10

Conservation

PhyloP100: 2.63

Publications

10 publications found
Variant links:
Genes affected
IDUA (HGNC:5391): (alpha-L-iduronidase) This gene encodes an enzyme that hydrolyzes the terminal alpha-L-iduronic acid residues of two glycosaminoglycans, dermatan sulfate and heparan sulfate. This hydrolysis is required for the lysosomal degradation of these glycosaminoglycans. Mutations in this gene that result in enzymatic deficiency lead to the autosomal recessive disease mucopolysaccharidosis type I (MPS I). [provided by RefSeq, Jul 2008]
IDUA Gene-Disease associations (from GenCC):
  • mucopolysaccharidosis type 1
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
  • Scheie syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), Orphanet
  • Hurler syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
  • Hurler-Scheie syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PS3
For more information check the summary or visit ClinGen Evidence Repository.
PM2
For more information check the summary or visit ClinGen Evidence Repository.
PM3
For more information check the summary or visit ClinGen Evidence Repository.
PP3
For more information check the summary or visit ClinGen Evidence Repository.
PP4
For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IDUANM_000203.5 linkc.1487C>G p.Pro496Arg missense_variant Exon 10 of 14 ENST00000514224.2 NP_000194.2 P35475-1
IDUANM_001363576.1 linkc.1091C>G p.Pro364Arg missense_variant Exon 9 of 13 NP_001350505.1
IDUAXM_047415650.1 linkc.1487C>G p.Pro496Arg missense_variant Exon 10 of 12 XP_047271606.1
IDUANR_110313.1 linkn.1575C>G non_coding_transcript_exon_variant Exon 10 of 14

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IDUAENST00000514224.2 linkc.1487C>G p.Pro496Arg missense_variant Exon 10 of 14 2 NM_000203.5 ENSP00000425081.2 P35475-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151960
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000139
AC:
2
AN:
143870
AF XY:
0.0000241
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000299
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000221
AC:
3
AN:
1359134
Hom.:
0
Cov.:
37
AF XY:
0.00000148
AC XY:
1
AN XY:
674164
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
28350
American (AMR)
AF:
0.00
AC:
0
AN:
33442
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23802
East Asian (EAS)
AF:
0.00
AC:
0
AN:
31192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
75728
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
35184
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5362
European-Non Finnish (NFE)
AF:
0.00000280
AC:
3
AN:
1069986
Other (OTH)
AF:
0.00
AC:
0
AN:
56088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151960
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74216
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41414
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10542
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67950
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000263
AC:
3

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:10
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 1 Pathogenic:6
Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Apr 24, 2018
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: IDUA c.1487C>G (p.Pro496Arg) 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. The variant was observed with an allele frequency of 1.4e-05 in 145584 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in IDUA causing Mucopolysaccharidosis Type 1 (1.4e-05 vs 0.0027), allowing no conclusion about variant significance. The variant, c.1487C>G, has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type 1 (Beesley_2001, Bertola_2011). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cites the variant as "pathogenic."Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 496 of the IDUA protein (p.Pro496Arg). This variant is present in population databases (rs772416503, gnomAD 0.003%). This missense change has been observed in individual(s) with Hurler syndrome (PMID: 21394825, 27520059). ClinVar contains an entry for this variant (Variation ID: 496861). 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 IDUA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects IDUA function (PMID: 11735025). For these reasons, this variant has been classified as Pathogenic. -

Jan 13, 2020
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The p.Pro496Arg variant in IDUA has been reported in at least 13 individuals with mucopolysaccharidosis (MPS) (PMID: 21394825, 28752568, 27520059) and has been identified in 0.003% (2/66872) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs772416503). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (VariationID: 496861) as pathogenic by Counsyl, EGL Genetic Diagnostics, and Integrated Genetics. In vitro functional studies provide some evidence that the p.Pro496Arg variant may impact protein function (PMID: 11735025). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The presence of this variant in combination with reported pathogenic variants and in at least 8 individuals with MPS increases the likelihood that the p.Pro496Arg variant is pathogenic (VariationID: 193061, 11909, 11908; PMID: 21394825, 28752568). One additional likely pathogenic variant, resulting in a different amino acid change at the same position, p.Pro496Leu, has been reported in association with disease in the literature and ClinVar, slightly supporting that a change at this position may not be tolerated (PMID: 7550232; Variation ID: 551675). In summary, this variant meets criteria to be classified as pathogenic for MPS in an autosomal recessive manner based on its presence in combination with other pathogenic variants in individuals with MPS and functional studies. ACMG/AMP Criteria applied: PM3_very-strong, PM2, PS3_moderate, PP3 (Richards 2015). -

Dec 05, 2024
ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel
Significance:Likely pathogenic
Review Status:reviewed by expert panel
Collection Method:curation

The NM_000203.5:c.1487C>G variant in IDUA is a missense variant predicted to cause substitution of Proline by Arginine at amino acid 496 p.(Pro496Arg). At least 8 patients are compound heterozygous for the variant and another variant in IDUA that has been classified as pathogenic or likely pathogenic by the ClinGen LD VCEP including c.793G>C (p.Gly265Arg) (ClinVar Variation ID: 638074) (PMID: 21394825, LP, 0.25), c.152G>A (p.Gly51Asp) (ClinVar Variation ID: 193061) (PMID: 21394825, P, 2 x 0.5), c.208C>T (p.Gln70Ter) (ClinVar Variation ID: 11909) (PMID: 21394825, P, 4 patients, max 2 x 0.5), and c.1598C>G (p.Pro533Arg) (PMID: 34408967, P, 0.5 points). One individual is homozygous for the variant (PMID: 34408967, 0.5 points). This variant has also been reported in compound heterozygosity with p.Arg89Trp (PMID: 21394825), c.1727+1G>A (PMID: 21394825), c.1854C>A (p.Tyr618Ter) (PMID: 27520059) and c.878_889dup (PMID 28752568). The allelic data from these patients will be used in the subsequent classification of then second variant and is not included here to avoid circular logic. Total 3.25 points (PM3_Strong). In one report (PMID: 27520059), there was evidence of decreased IDUA enzyme activity, increased urine glycosaminoglycans and a specific clinical phenotype, allowing for application of PP4_Moderate. The highest population minor allele frequency in gnomAD v4.1.0. is 0.000003515 (4/1137936 alleles) in the European (non-Finnish) population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.00025), meeting this criterion (PM2_Supporting). and has some experimental evidence suggesting absence of IDUA activity when the variant is expressed in Cos-7 cells (PMID: 11735025) (PS3_Supporting). Computational predictor tools (REVEL score 0.72) suggest that this variant may be deleterious to IDUA function (PP3). A different missense variant, c.1487C>G (p.Pro496Leu) [ClinVar Variation ID 551675] in the same codon has been classified as likely pathogenic for MPS I by the ClinGen VCEP, however PM5 was not assigned to avoid circular logic. There is a ClinVar entry for this variant (Variation ID: 496861). In summary, this variant meets the criteria to be classified as likely pathogenic for MPS I based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert panel: PM3_Strong, PP4_Moderate. PS3_Supporting, PM2_Supporting, PP3. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) -

Jan 01, 2019
Laboratory of Diagnosis and Therapy of Lysosomal Disorders, University of Padova
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:literature only

PS3: Low in vitro enzymatic activity. PM2: Very low frequency in ExAC. PP3: Multiple lines of computational evidence supporting a deleterious effect -

not provided Pathogenic:2
Jul 15, 2022
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 30, 2017
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hurler syndrome Pathogenic:1
Mar 21, 2017
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Mucopolysaccharidosis, MPS-I-S;C0086431:Mucopolysaccharidosis, MPS-I-H/S;C0086795:Hurler syndrome Pathogenic:1
May 06, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.25
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.97
D;.
Eigen
Uncertain
0.47
Eigen_PC
Uncertain
0.32
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Uncertain
0.88
D;.
M_CAP
Pathogenic
0.85
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
0.99
D
MutationAssessor
Uncertain
2.7
M;.
PhyloP100
2.6
PrimateAI
Pathogenic
0.88
D
PROVEAN
Pathogenic
-7.6
D;D
REVEL
Pathogenic
0.72
Sift
Uncertain
0.0020
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;.
Vest4
0.85
MVP
0.99
MPC
0.75
ClinPred
0.99
D
GERP RS
3.9
Varity_R
0.93
gMVP
0.94
Mutation Taster
=3/97
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs772416503; hg19: chr4-996908; API