chr4-1004292-C-T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000203.5(IDUA):​c.1861C>T​(p.Arg621*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,610,956 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R621R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

IDUA
NM_000203.5 stop_gained

Scores

3
3
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 1.51

Publications

23 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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 23 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 4-1004292-C-T is Pathogenic according to our data. Variant chr4-1004292-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 11917.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IDUANM_000203.5 linkc.1861C>T p.Arg621* stop_gained Exon 14 of 14 ENST00000514224.2 NP_000194.2 P35475-1
IDUANM_001363576.1 linkc.1465C>T p.Arg489* stop_gained Exon 13 of 13 NP_001350505.1
IDUANR_110313.1 linkn.1953C>T non_coding_transcript_exon_variant Exon 14 of 14
IDUAXM_047415650.1 linkc.*300C>T downstream_gene_variant XP_047271606.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IDUAENST00000514224.2 linkc.1861C>T p.Arg621* stop_gained Exon 14 of 14 2 NM_000203.5 ENSP00000425081.2 P35475-1
IDUAENST00000247933.9 linkc.1861C>T p.Arg621* stop_gained Exon 14 of 14 1 ENSP00000247933.4 P35475-1
IDUAENST00000514698.5 linkn.1972C>T non_coding_transcript_exon_variant Exon 11 of 11 5
IDUAENST00000652070.1 linkn.1917C>T non_coding_transcript_exon_variant Exon 13 of 13

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151964
Hom.:
0
Cov.:
32
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000282
AC:
7
AN:
248290
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000145
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000890
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000137
AC:
20
AN:
1458876
Hom.:
0
Cov.:
32
AF XY:
0.0000110
AC XY:
8
AN XY:
725876
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.000112
AC:
5
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86256
European-Finnish (FIN)
AF:
0.0000198
AC:
1
AN:
50488
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1111970
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60364
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.447
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152080
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41470
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5146
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67976
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 1 Pathogenic:5
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.Arg621Ter variant in IDUA has been reported in at least 4 individuals with mucopolysaccharidosis (MPS) (PMID: 11735025, 7951228, 27146977, 7550242) and has been identified in 0.014% (5/34554) of Latino chromosomes, 0.003% (1/30604) of South Asian chromosomes and 0.001% (1/112398) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs121965025). 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: 11917) as pathogenic by Counsyl, Integrated Genetics, and OMIM. This nonsense variant leads to a premature termination codon at position 621. This alteration occurs within the last exon and is more likely to escape nonsense mediated decay (NMD) and result in a truncated protein. Loss of function of the IDUA gene is an established disease mechanism in autosomal recessive MPS. The presence of this variant in 1 affected homozygote and in combination with reported pathogenic variants in 2 individuals with MPS increases the likelihood that the p.Arg621Ter variant is pathogenic (VariationID: 11908, 550799; PMID: 11735025, 7951228, 27146977). The phenotype of an individual compound heterozygous for this variant is highly specific for MPS based on alpha-L-iduronidase activity being <1% of normal consistent with disease (PMID: 23786846). In summary, this variant meets criteria to be classified as pathogenic for MPS in an autosomal recessive manner based on the prediction that the variant will cause loss of function, the presence of the variant in affected homozygotes and compound heterozygotes, and the phenotype of an individual with this variant being highly specific for MPS. ACMG/AMP Criteria applied: PVS1_strong, PM3_strong, PM2_supporting, PP4 (Richards 2015). -

Apr 21, 2021
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Oct 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg621*) in the IDUA gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 33 amino acid(s) of the IDUA protein. This variant is present in population databases (rs121965025, gnomAD 0.01%). This premature translational stop signal has been observed in individuals with mucopolysaccharidosis type 1 (PMID: 7550242, 7951228, 21394825, 23786846, 27146977, 28752568). ClinVar contains an entry for this variant (Variation ID: 11917). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts a region of the IDUA protein in which other variant(s) (p.Trp626*) have been determined to be pathogenic (PMID: 19396826, 21462124, 28752568). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Aug 20, 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.1861C>T (p.Arg621X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.5e-05 in 243934 control chromosomes (gnomAD and publications). The variant, c.1861C>T, has been reported in the literature in individuals affected with Mucopolysaccharidosis Type 1 (Uttarilli_2016, Bunge_1994, Oussorena_2013). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function (Uttarilli_2016). The most pronounced variant effect results in <10% of normal activity. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Aug 05, 2020
Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This nonsense variant is found in exon 14 of 14 and is predicted to result in the disruption of the final 33 amino acids of the protein. This variant has been previously reported as compound heterozygous or homozygous change in patients with Mucopolysaccharidosis type I (PMID: 7951228, 27146977, 23786846, 21394825). Functional characterization of the variant indicates that it reduces enzyme activity to less than 10% residual activity (PMID: 23786846). It is present in the heterozygous state in the gnomAD population database at a frequency of 0.003% (7/248290) and thus is presumed to be rare. Based on the available evidence, the c.1861C>T (p.Arg621Ter) variant is classified as Pathogenic. -

Hurler syndrome Pathogenic:2
Jun 01, 1994
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jun 30, 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. -

not provided Pathogenic:1
Jul 30, 2022
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mucopolysaccharidosis, MPS-I-S;C0086431:Mucopolysaccharidosis, MPS-I-H/S;C0086795:Hurler syndrome Pathogenic:1
Jan 10, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.45
D
BayesDel_noAF
Pathogenic
0.62
CADD
Pathogenic
38
DANN
Uncertain
1.0
Eigen
Pathogenic
0.69
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.96
D
PhyloP100
1.5
Vest4
0.80
GERP RS
4.7
Mutation Taster
=0/200
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: rs121965025; hg19: chr4-998080; COSMIC: COSV56102412; COSMIC: COSV56102412; API