4-1002325-C-G
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PP4PM2_SupportingPM3_StrongPVS1
This summary comes from the ClinGen Evidence Repository: The NM_000203.5(IDUA):c.1029C>G (p.Tyr343Ter) variant is a nonsense variant observed to cause a premature stop codon in biologically relevant exon 8 (out of 14), leading to nonsense-mediated decay in the IDUA gene in which loss-of-function is an established disease mechanism. Expression of the variant in COS-7 cells showed 1.1% of normal IDUA activity (PMID:9391892) (PVS1). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00006 (1/15956 alleles) in the African population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.0025), meeting this criterion (PM2_Supporting). This variant has been detected in at least 3 individuals with MPS I. Of those individuals, 2 were heterozygous for the variant and a pathogenic or likely pathogenic variant (variants are: c.208C>T (p.Gln70Ter), c.3G>A (p.Met1?)), and one of those was confirmed in trans (PMIDs: 15081804, 9391892, 8019572) (PM3_Strong). At least 1 patient with this variant had undetectable IDUA activity in skin fibroblasts (PP4) (PMID:15081804). There is a ClinVar entry for this variant (Variation ID: 550474). In summary, this variant meets the criteria to be classified as pathogenic for MPS I based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert Panel (Specifications Version 1.0.0): PVS1, PM2_Supporting, PM3_Strong, PP4.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA2802166/MONDO:0001586/010
Frequency
Consequence
NM_000203.5 stop_gained
Scores
Clinical Significance
Conservation
Publications
- mucopolysaccharidosis type 1Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
- Scheie syndromeInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), Orphanet
- Hurler syndromeInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
- Hurler-Scheie syndromeInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| IDUA | NM_000203.5 | c.1029C>G | p.Tyr343* | stop_gained | Exon 8 of 14 | ENST00000514224.2 | NP_000194.2 | |
| IDUA | NM_001363576.1 | c.633C>G | p.Tyr211* | stop_gained | Exon 7 of 13 | NP_001350505.1 | ||
| IDUA | XM_047415650.1 | c.1029C>G | p.Tyr343* | stop_gained | Exon 8 of 12 | XP_047271606.1 | ||
| IDUA | NR_110313.1 | n.1117C>G | non_coding_transcript_exon_variant | Exon 8 of 14 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| IDUA | ENST00000514224.2 | c.1029C>G | p.Tyr343* | stop_gained | Exon 8 of 14 | 2 | NM_000203.5 | ENSP00000425081.2 | ||
| IDUA | ENST00000247933.9 | c.1029C>G | p.Tyr343* | stop_gained | Exon 8 of 14 | 1 | ENSP00000247933.4 | |||
| IDUA | ENST00000514698.5 | n.1136C>G | non_coding_transcript_exon_variant | Exon 5 of 11 | 5 | |||||
| IDUA | ENST00000652070.1 | n.1085C>G | non_coding_transcript_exon_variant | Exon 7 of 13 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152270Hom.: 0 Cov.: 34 show subpopulations
GnomAD2 exomes AF: 0.00000403 AC: 1AN: 248154 AF XY: 0.00000742 show subpopulations
GnomAD4 exome Cov.: 35
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152270Hom.: 0 Cov.: 34 AF XY: 0.0000269 AC XY: 2AN XY: 74398 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Mucopolysaccharidosis type 1 Pathogenic:3
This sequence change creates a premature translational stop signal (p.Tyr343*) in the IDUA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IDUA are known to be pathogenic (PMID: 11735025, 21480867). This variant is present in population databases (rs764196171, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with mucopolysaccharidosis type I (PMID: 8019572, 9391892, 31298590). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 550474). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
The NM_000203.5(IDUA):c.1029C>G (p.Tyr343Ter) variant is a nonsense variant observed to cause a premature stop codon in biologically relevant exon 8 (out of 14), leading to nonsense-mediated decay in the IDUA gene in which loss-of-function is an established disease mechanism. Expression of the variant in COS-7 cells showed 1.1% of normal IDUA activity (PMID: 9391892) (PVS1). The highest population minor allele frequency in gnomAD v2.1.1 is 0.00006 (1/15956 alleles) in the African population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.0025), meeting this criterion (PM2_Supporting). This variant has been detected in at least 3 individuals with MPS I. Of those individuals, 2 were heterozygous for the variant and a pathogenic or likely pathogenic variant (variants are: c.208C>T (p.Gln70Ter), c.3G>A (p.Met1?)), and one of those was confirmed in trans (PMIDs: 15081804, 9391892, 8019572) (PM3_Strong). At least 1 patient with this variant had undetectable IDUA activity in skin fibroblasts (PP4) (PMID: 15081804). There is a ClinVar entry for this variant (Variation ID: 550474). In summary, this variant meets the criteria to be classified as pathogenic for MPS I based on the ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert Panel (Specifications Version 1.0.0): PVS1, PM2_Supporting, PM3_Strong, PP4. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) -
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not provided Pathogenic:2
Published functional studies demonstrate that IDUA activity is significantly reduced compared to wildtype (PMID: 9391892); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 31298590, 31133280, 29976218, 28676128, 21734815, 28367323, 8019572, 37542767, 9391892, 35141277, 9787109, 23837464, 15081804) -
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Hurler syndrome Pathogenic:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at