chr4-1001802-T-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_000203.5(IDUA):c.713T>A(p.Leu238Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000561 in 1,604,640 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

IDUA
NM_000203.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 6.04

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.973

PP5

Variant 4-1001802-T-A is Pathogenic according to our data. Variant chr4-1001802-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 265418.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
IDUA	NM_000203.5 link	c.713T>A	p.Leu238Gln	missense_variant	Exon 6 of 14	ENST00000514224.2	NP_000194.2	P35475-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IDUA	ENST00000514224.2 link	c.713T>A	p.Leu238Gln	missense_variant	Exon 6 of 14	2	NM_000203.5	ENSP00000425081.2		P35475-1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

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

GnomAD3 exomes

AF:

0.0000218

AC:

AN:

229094

Hom.:

AF XY:

0.0000239

AC XY:

AN XY:

125528

show subpopulations

Gnomad AFR exome

AF:

0.000144

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000291

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000413

AC:

AN:

1452456

Hom.:

Cov.:

AF XY:

0.00000554

AC XY:

AN XY:

722324

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000451

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.0000482

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000283

Hom.:

Bravo

AF:

0.0000113

ESP6500AA

AF:

0.000228

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000831

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 1

Pathogenic:3

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jan 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with glutamine, which is neutral and polar, at codon 238 of the IDUA protein (p.Leu238Gln). This variant is present in population databases (rs148789453, gnomAD 0.008%). This missense change has been observed in individual(s) with mucopolysaccharidosis type I (PMID: 15300847, 24368159; Invitae). ClinVar contains an entry for this variant (Variation ID: 265418). 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%. This variant disrupts the p.Leu238 amino acid residue in IDUA. Other variant(s) that disrupt this residue have been observed in individuals with IDUA-related conditions (PMID: 21480867, 24368159), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Jan 14, 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.Leu238Gln variant in IDUA has been reported in at least 7 individuals with mucopolysaccharidosis (MPS), segregated with disease in 4 affected relatives from 2 families (PMID: 24368159), and has been Identified in 0.014% (2/13914) of African chromosomes and 0.003% (3/102956) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs148789453). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. In vitro functional studies provide some evidence that the p.Leu238Gln variant may impact protein function (PMID: 15300847). 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 in 5 individuals with MPS increases the likelihood that the p.Leu238Gln variant is pathogenic (VariationID: 11908, 222994; PMID: 24368159). The phenotype of individuals compound heterozygous for this variant is highly specific for MPS based on alpha-L-iduronidase activity being <1%, consistent with disease (PMID: 15300847). In summary, this variant meets criteria to be classified as pathogenic for MPS in an autosomal recessive manner based on the presence of the variant in combination with known pathogenic variants, functional studies, cosegregation, and the phenotype of individuals with the variant and MPS being highly specific for IDUA. ACMG/AMP Criteria applied: PM3_strong, PS3_moderate, PM2_supporting, PP3, PP4, PP1 (Richards 2015). -

not provided

Pathogenic:2

Nov 07, 2020

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 31, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Published functional studies demonstrate that the L238Q variant causes reduced IDUA activity and protein levels when expressed in Chinese hamster ovary (CHO) cells (Yogalingam et al., 2004); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 15300847, 24368159, 26260077, 31194252) -

IDUA-related disorder

Pathogenic:1

Jun 18, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The IDUA c.713T>A variant is predicted to result in the amino acid substitution p.Leu238Gln. This variant was reported along with second variant in several individuals with Mucopolysaccharidosis type 1 (Yogalingam et al. 2004. PubMed ID: 15300847; Ahmed et al. 2013. PubMed ID: 24368159). In vitro functional study demonstrated that this variant reduces IDUA activity to 5.88% of normal enzyme activity (Table 3, Yogalingam et al. 2004. PubMed ID: 15300847). Alternative variant at the same codon p.Leu238Arg has been observed in an individual with Mucopolysaccharidosis type 1 (Wang et al. 2011. PubMed ID: 21480867). This variant is reported in 0.014% of alleles in individuals of African descent in gnomAD. This variant is interpreted as pathogenic. -

Hurler syndrome

Pathogenic:1

Aug 10, 2017

Counsyl

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

0.89

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.97

D;.;D;D;.

Eigen

Uncertain

0.65

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.78

T;T;.;.;.

M_CAP

Pathogenic

0.75

MetaRNN

Pathogenic

0.97

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.7

M;.;.;.;.

PrimateAI

Uncertain

0.65

PROVEAN

Pathogenic

-5.3

D;D;D;D;D

REVEL

Pathogenic

0.90

Sift

Uncertain

0.0020

D;D;D;D;D

Sift4G

Uncertain

0.0020

D;D;D;D;D

Polyphen

1.0

D;.;.;.;.

Vest4

0.91

MVP

1.0

MPC

0.77

ClinPred

0.95

GERP RS

5.4

Varity_R

0.94

gMVP

0.98

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

Details are displayed if max score is > 0.2

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over