NM_000203.5:c.1614delG
Variant summary
Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PP4PM2_SupportingPM3
This summary comes from the ClinGen Evidence Repository: The NM_000203.5:c.1614del (p.His539ThrfsTer21) variant in IDUA is a frameshift variant predicted to cause a premature stop codon in biologically relevant exon 11/20 leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant has been detected in at least 4 individuals with MPS I, with documented IDUA deficiency within the affected range in leukocytes (PMID:8213840, 15300847, 19396826, 35141277) and/or clinical features specific to MPS I including short stature, joint stiffness, progressive developmental decline, severe hepatosplenomegaly, systolic murmur, mitral valve defects, umbilical hernia, hirsutism, large tongue, corneal clouding (PMID:15300847, 19396826) (PP4). Of these individuals, at least 3 were compound heterozygous for the variant and another variant in IDUA, phase unconfirmed, that has been classified as pathogenic by the ClinGen LD VCEP including c.208C>T (p.Gln70Ter) (ClinVar Variation ID: 11909) (PMID:8213840, 15300847, 35141277, 2 or 3 patients; max 2 x 0.5 points), and c.1205G>A (p.Trp402Ter) (ClinVar Variation ID: 11908) (PMID:25614311, 0.5 points). Another patient is compound heterozygous for the variant and c.1650+5G>A (PMID:19396826). The allelic data from this patient will be used in the classification of c.1650+5G>A and is not included here to avoid circular logic. Total 1.5 points (PM3). The highest population minor allele frequency in gnomAD v4.1.0. is 0.000001741 (2/1148676 alleles) in the NFE population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.00025), meeting this criterion (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID: 167191). In summary, this variant meets the criteria to be classified as Pathogenic for MPS I based on the IDUA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert Panel (Specifications Version 1.0.0): PVS1, PM2_Supporting, PM3_Moderate, PP4.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA234129/MONDO:0001586/091
Frequency
Consequence
NM_000203.5 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152078Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000145 AC: 2AN: 137732Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 75288
GnomAD4 exome AF: 0.00000721 AC: 10AN: 1386478Hom.: 0 Cov.: 33 AF XY: 0.00000438 AC XY: 3AN XY: 684778
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152078Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74296
ClinVar
Submissions by phenotype
Mucopolysaccharidosis type 1 Pathogenic:5
The NM_000203.5:c.1614del (p.His539ThrfsTer21) variant in IDUA is a frameshift variant predicted to cause a premature stop codon in biologically relevant exon 11/20 leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant has been detected in at least 4 individuals with MPS I, with documented IDUA deficiency within the affected range in leukocytes (PMID: 8213840, 15300847, 19396826, 35141277) and/or clinical features specific to MPS I including short stature, joint stiffness, progressive developmental decline, severe hepatosplenomegaly, systolic murmur, mitral valve defects, umbilical hernia, hirsutism, large tongue, corneal clouding (PMID: 15300847, 19396826) (PP4). Of these individuals, at least 3 were compound heterozygous for the variant and another variant in IDUA, phase unconfirmed, that has been classified as pathogenic by the ClinGen LD VCEP including c.208C>T (p.Gln70Ter) (ClinVar Variation ID: 11909) (PMID: 8213840, 15300847, 35141277, 2 or 3 patients; max 2 x 0.5 points), and c.1205G>A (p.Trp402Ter) (ClinVar Variation ID: 11908) (PMID: 25614311, 0.5 points). Another patient is compound heterozygous for the variant and c.1650+5G>A (PMID: 19396826). The allelic data from this patient will be used in the classification of c.1650+5G>A and is not included here to avoid circular logic. Total 1.5 points (PM3). The highest population minor allele frequency in gnomAD v4.1.0. is 0.000001741 (2/1148676 alleles) in the NFE population, which is lower than the ClinGen Lysosomal Diseases VCEP’s threshold for PM2_Supporting (<0.00025), meeting this criterion (PM2_Supporting). There is a ClinVar entry for this variant (Variation ID: 167191). In summary, this variant meets the criteria to be classified as Pathogenic for MPS I based on the IDUA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases Variant Curation Expert Panel (Specifications Version 1.0.0): PVS1, PM2_Supporting, PM3_Moderate, PP4. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 5, 2024) -
The p.His539ThrfsTer21 variant in IDUA has been reported in at least 2 individuals with mucopolysaccharidosis (MPS) (PMID: 19396826, 8213840) and has been identified in 0.012% (1/8140) of Ashkenazi Jewish chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP 167191). 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: 167191) as pathogenic by EGL Genetic Diagnostics and Counsyl. This variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at position 539 and leads to a premature termination codon 21 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the IDUA gene is an established disease mechanism in autosomal recessive MPS. The presence of this variant in combination with a reported pathogenic variant in an individual with MPS slightly increases the likelihood that the p.His539ThrfsTer21 variant is pathogenic (VariationID: 11909; VariationID: 8213840). The phenotype of an individual compound heterozygous for this variant is highly specific for MPS based on null alpha-L-iduronidase protein activity, consistent with disease (PMID: 8213840). In summary, this variant meets criteria to be classified as pathogenic for MPS in an autosomal recessive manner based on the prediction that it will cause loss of function of the IDUA gene, the presence of the variant in combination with pathogenic variants, and the phenotype of an individual with the variant being highly specific for MPS. ACMG/AMP Criteria applied: PVS1, PM3_supporting, PM2_supporting, PP4 (Richards 2015). -
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This sequence change creates a premature translational stop signal (p.His539Thrfs*21) 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 (rs727503967, gnomAD 0.03%). This premature translational stop signal has been observed in individuals with mucopolysaccharidosis type I (PMID: 8213840, 19396826). This variant is also known as delG1702. ClinVar contains an entry for this variant (Variation ID: 167191). For these reasons, this variant has been classified as Pathogenic. -
Variant summary: IDUA c.1614delG (p.His539ThrfsX21) 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. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.5e-05 in 137732 control chromosomes. c.1614delG has been reported in the literature in individuals affected with Mucopolysaccharidosis Type 1 (Scott_1993, Vazna_2009). These data indicate that the variant may be associated with disease. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:2
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Hurler syndrome Pathogenic:2
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Mucopolysaccharidosis, MPS-I-S;C0086431:Mucopolysaccharidosis, MPS-I-H/S;C0086795:Hurler syndrome Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at