rs398123260

Variant summary

Our verdict is Pathogenic. Variant got 7 ACMG points: 7P and 0B. PS3_SupportingPP4PM3PM2_SupportingPM4

This summary comes from the ClinGen Evidence Repository: The NM_000203.5:c.46_57del variant results in an inframe deletion of 4 amino acids (p.Ser16_Ala19del) within the lysosomal signal sequence of IDUA (PM4). This variant is named "134del12" in older literature. At least twelve patients with with variant and a diagnosis of mucopolysaccharidosis type 1 have been reported in the literature. This includes four patients with documented laboratory values showing deficiency of IDUA activity in fibroblasts or leukocytes (PMID:15300847, 21394825, 23786846) one of whom also had documented clinical features consistent with the diagnosis including corneal clouding, joint stiffness, digital contractures, cardiac valve disease, airway obstruction, and developmental delay (PMID:15300847) (PP4). Four individuals have been reported who are compound heterozygous for the variant and another variant in IDUA that has been classified as pathogenic by the ClinGen Lysosomal Diseases VCEP including two confirmed in trans - c.1750C>T (p.Gln584Ter) (PMID:12189649) and p.Trp402Ter (PMID:11735025); and two phase unknown - c.208C>T (p.Gln70Ter) (PMID:21394825) and c.386-2A>G (PMID:11735025). In addition, at least two homozygotes have been reported PMID:7951228, 21394825) (PM3_VeryStrong). Additional patients are compound heterozygous for the variant and c.603C>G (p.Tyr201Ter) (PMID:21394825), c.1189+5G>A (PMID:21394825); c.1960T>C (p.Ter654ArgextTer*62) (PMID:21394825), c.1049A>T (p.Asn350Ile) (PMID:12559846) and c.1598C>G (p.Pro533Arg) (PMID:15300847). The allelic data from these patients will be used in the classification of the second variant and is not included here to avoid circular logic. When expressed in COS-7 cells, the variant (labeled as "134del12") resulted in 124.6% of normal activity. A 77-kDa precursor protein was observed on Western blot, compared with a major mature 63-kDa form and a minor 77-kDa precursor in cells transfected with wild-type cDNA. These results suggested that the variant prevents correct posttranslational processing and transport to the lysosome (PMID:12189649) (PS3_Supporting). The highest population minor allele frequency in gnomAD v4.1.0 is 0.00006251 (69/1103836 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). There is a ClinVar entry for this variant (Variation ID: 92643). In summary, this variant meets the criteria to be classified as pathogenic for mucopolysaccharidosis type 1. IDUA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases VCEP (Specifications Version 1.0.0): PM3_Very Strong, PM4, PP4, PS3_Supporting, PM2_Supporting.(Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 6, 2024) LINK:https://erepo.genome.network/evrepo/ui/classification/CA220509/MONDO:0001586/091

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 36)
Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

IDUA
NM_000203.5 conservative_inframe_deletion

Scores

Not classified

Clinical Significance

Pathogenic reviewed by expert panel P:12

Conservation

PhyloP100: 0.445
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]
SLC26A1 (HGNC:10993): (solute carrier family 26 member 1) This gene is a member of a family of sulfate/anion transporter genes. Family members are well conserved in their genomic (number and size of exons) and protein (aa length among species) structures, but have markedly different tissue expression patterns. This gene is primarily expressed in the liver, pancreas, and brain. Three splice variants that encode different isoforms have been identified. [provided by RefSeq, Jul 2008]
DGKQ (HGNC:2856): (diacylglycerol kinase theta) The protein encoded by this gene contains three cysteine-rich domains, a proline-rich region, and a pleckstrin homology domain with an overlapping Ras-associating domain. It is localized in the speckle domains of the nucleus, and mediates the regeneration of phosphatidylinositol (PI) from diacylglycerol in the PI-cycle during cell signal transduction. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 7 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.
PM4
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.46_57delTCGCTCCTGGCC p.Ser16_Ala19del conservative_inframe_deletion Exon 1 of 14 ENST00000514224.2 NP_000194.2 P35475-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IDUAENST00000514224.2 linkc.46_57delTCGCTCCTGGCC p.Ser16_Ala19del conservative_inframe_deletion Exon 1 of 14 2 NM_000203.5 ENSP00000425081.2 P35475-1

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152036
Hom.:
0
Cov.:
36
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.000118
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000495
AC:
64
AN:
1293482
Hom.:
0
AF XY:
0.0000596
AC XY:
38
AN XY:
637434
show subpopulations
Gnomad4 AFR exome
AF:
0.0000384
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000362
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000589
Gnomad4 OTH exome
AF:
0.0000188
GnomAD4 genome
AF:
0.0000592
AC:
9
AN:
152036
Hom.:
0
Cov.:
36
AF XY:
0.0000269
AC XY:
2
AN XY:
74276
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000118
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000642

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:12
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 1 Pathogenic:5
Jul 24, 2020
Natera, Inc.
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Dec 06, 2024
ClinGen Lysosomal Storage Disorder Variant Curation Expert Panel
Significance: Pathogenic
Review Status: reviewed by expert panel
Collection Method: curation

The NM_000203.5:c.46_57del variant results in an inframe deletion of 4 amino acids (p.Ser16_Ala19del) within the lysosomal signal sequence of IDUA (PM4). This variant is named "134del12" in older literature. At least twelve patients with with variant and a diagnosis of mucopolysaccharidosis type 1 have been reported in the literature. This includes four patients with documented laboratory values showing deficiency of IDUA activity in fibroblasts or leukocytes (PMID: 15300847, 21394825, 23786846) one of whom also had documented clinical features consistent with the diagnosis including corneal clouding, joint stiffness, digital contractures, cardiac valve disease, airway obstruction, and developmental delay (PMID: 15300847) (PP4). Four individuals have been reported who are compound heterozygous for the variant and another variant in IDUA that has been classified as pathogenic by the ClinGen Lysosomal Diseases VCEP including two confirmed in trans - c.1750C>T (p.Gln584Ter) (PMID: 12189649) and p.Trp402Ter (PMID: 11735025); and two phase unknown - c.208C>T (p.Gln70Ter) (PMID: 21394825) and c.386-2A>G (PMID: 11735025). In addition, at least two homozygotes have been reported PMID: 7951228, 21394825) (PM3_VeryStrong). Additional patients are compound heterozygous for the variant and c.603C>G (p.Tyr201Ter) (PMID: 21394825), c.1189+5G>A (PMID: 21394825); c.1960T>C (p.Ter654ArgextTer*62) (PMID: 21394825), c.1049A>T (p.Asn350Ile) (PMID: 12559846) and c.1598C>G (p.Pro533Arg) (PMID: 15300847). The allelic data from these patients will be used in the classification of the second variant and is not included here to avoid circular logic. When expressed in COS-7 cells, the variant (labeled as "134del12") resulted in 124.6% of normal activity. A 77-kDa precursor protein was observed on Western blot, compared with a major mature 63-kDa form and a minor 77-kDa precursor in cells transfected with wild-type cDNA. These results suggested that the variant prevents correct posttranslational processing and transport to the lysosome (PMID: 12189649) (PS3_Supporting). The highest population minor allele frequency in gnomAD v4.1.0 is 0.00006251 (69/1103836 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). There is a ClinVar entry for this variant (Variation ID: 92643). In summary, this variant meets the criteria to be classified as pathogenic for mucopolysaccharidosis type 1. IDUA-specific ACMG/AMP criteria applied, as specified by the ClinGen Lysosomal Diseases VCEP (Specifications Version 1.0.0): PM3_Very Strong, PM4, PP4, PS3_Supporting, PM2_Supporting. (Classification approved by the ClinGen Lysosomal Diseases Variant Curation Expert Panel on December 6, 2024) -

Apr 11, 2023
Illumina Laboratory Services, Illumina
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The IDUA c.46_57del (p.Ser16_Ala19del) variant, also referred to as 134del12, is an in-frame deletion of four amino acids at amino acid position 16. The c.46_57del variant has been reported in both a homozygous and compound heterozygous state in multiple individuals with phenotypes consistent with mucopolysaccharidosis type I (PMID: 7951228; PMID: 11735025; PMID: 12189649; PMID: 15300847; PMID: 21480867). This variant is reported in the Genome Aggregation Database in two alleles at a frequency of 0.000130 in the European (non-Finnish) population (version 2.1.1). Functional studies conducted in patient cells suggest that this variant results in decreased enzyme activity and may prevent posttranslational processing and transport into the lysosome (PMID: 12189649; PMID: 23786846). Based on the available evidence, the c.46_57del (p.Ser16_Ala19del) variant is classified as pathogenic for mucopolysaccharidosis type I. -

Jun 30, 2016
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: The IDUA c.46_57del12 (Ser16_Ala19del) variant result in an in frame deletion of 4 amino acids that are not located in a known functional domain of Alpha-L-iduronidase. One in silico tool predicts a benign outcome for this variant. Functional studies in cultured skin fibroblasts from patients compound heterozygous for this variant have indicated that this variant results in IDUA activity that is lower than heterozygous carriers. It has been suggested that although the precursor Ser16_Ala19del IDUA is enzymatically active, this may prevent correct post-translational processing and transport to the lysosome (Lee-Chen_J Formos Med Assoc_2002 ). This variant was absent in 6918 control chromosomes, but has been identified in many compound heterozygous MPS1 patients reported in the literature. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Nov 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant, c.46_57del, results in the deletion of 4 amino acid(s) of the IDUA protein (p.Ser16_Ala19del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs398123260, gnomAD 0.01%). This variant has been observed in individual(s) with mucopolysacccharidosis (MPS) type I (PMID: 7951228, 12189649, 15300847, 21394825). 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: 92643). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects IDUA function (PMID: 12189649). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:3
Mar 22, 2016
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 26, 2023
Revvity Omics, Revvity
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 18, 2025
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

In-frame deletion of 4 of amino acid(s)in a non-repeat region predicted to critically alter the protein; In silico analysis supports a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 23786846, 15300847, 28604952, 21734815, 25098213, 7951228, 11735025, 21394825, Fenton-Navarro2017[CaseReport], 12189649, 37218880, 34813777, 30548430, 21480867) -

Mucopolysaccharidosis, MPS-I-S Pathogenic:1
-
Neuberg Centre For Genomic Medicine, NCGM
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The inframe deletion c.46_57del variant has been reported previously in patient affected with Mucopolysaccharidosis Is (Izumi et. al., 2018) and has also been reported in multiple unrelated individuals affected with MPS I (Bertola et. al., 2011; Yogalingam et. al., 2004; Bunge et. al., 1994). Experimental studies have shown that this variant change results in a IDUA protein that is not cleaved post-translationally, which may prevent its proper localization to the lysosome and interfere with its normal function despite its increased enzymatic activity (Lee-Chen et. al., 2002). The p.Ser16_Ala19del variant is novel (not in any individuals) in gnomAD Exomes and 1000 Genomes and has an allele frequency of 0.006415% in gnomAD database. This variant has been reported to the ClinVar database as Pathogenic. This p.Ser16_Ala19del causes deletion of amino acid Serine at position 16 to Alanine at position 19. This variant is not in the repeat region. For these reasons, this variant has been classified as Pathogenic. -

IDUA-related disorder Pathogenic:1
Dec 01, 2022
PreventionGenetics, part of Exact Sciences
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The IDUA c.46_57del12 variant is predicted to result in an in-frame deletion (p.Ser16_Ala19del). This variant is also referred to as 134del12 in the literature. This variant has been reported in the homozygous and compound heterozygous states in individuals with biochemically confirmed mucopolysaccharidosis IH, also referred to as Hurler syndrome (Table 1, Bunge et al. 1994. PubMed ID: 7951228; Lee-Chen et al. 2002. PubMed ID: 12189649; Table 4, Gheldof et al. 2018. PubMed ID: 30548430; Table 2, Fang et al. 2021. PubMed ID: 34813777). Experimental studies using patient derived fibroblasts indicate this variant abolishes IDUA activity (Table 1, Oussoren et al. 2013. PubMed ID: 23786846). This variant is reported in 0.013% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/4-980906-GCGCTCCTGGCCT-G). This variant is interpreted as pathogenic. -

Hurler syndrome Pathogenic:1
-
Pathology and Clinical Laboratory Medicine, King Fahad Medical City
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
May 02, 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

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs398123260; hg19: chr4-980906; API