rs758452450

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2PM5PP3_StrongPP5_Very_Strong

The NM_000203.5(IDUA):c.223G>A(p.Ala75Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,611,924 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A75V) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

IDUA
NM_000203.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.51

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:

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]

SLC26A1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr4-987874-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1464729.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.982

PP5

Variant 4-987873-G-A is Pathogenic according to our data. Variant chr4-987873-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 222993.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IDUA	NM_000203.5 linkuse as main transcript	c.223G>A	p.Ala75Thr	missense_variant	2/14	ENST00000514224.2
SLC26A1	NM_022042.4 linkuse as main transcript	c.*960C>T		3_prime_UTR_variant	3/3	ENST00000398516.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IDUA	ENST00000514224.2 linkuse as main transcript	c.223G>A	p.Ala75Thr	missense_variant	2/14	2	NM_000203.5	P1	P35475-1
SLC26A1	ENST00000398516.3 linkuse as main transcript	c.*960C>T		3_prime_UTR_variant	3/3	1	NM_022042.4	P1	Q9H2B4-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000827

AC:

AN:

241700

Hom.:

AF XY:

0.00000759

AC XY:

AN XY:

131768

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.0000188

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1459778

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

726154

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:

0.0000126

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152146

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74304

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000383

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000166

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Mucopolysaccharidosis type 1

Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 31, 2021	Variant summary: IDUA c.223G>A (p.Ala75Thr) results in a non-conservative amino acid change located in the Glycoside hydrolase domain (IPR000514) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.3e-06 in 241700 control chromosomes. c.223G>A has been reported in the literature in multiple individuals affected with Mucopolysaccharidosis Type 1 (example, Clarke_1994, Ghosh_2017). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (example, Tieu_1995). Four clinical diagnostic laboratories and the Gene Reviews database have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 13, 2020	The p.Ala75Thr variant in IDUA has been reported in at least 9 individuals with mucopolysaccharidosis (MPS) (PMID: 29843745, 27146977, 28752568) and has been identified in 0.002% (3/121916) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs758452450). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (VariationID: 222993) as pathogenic by Counsyl and GeneReviews. 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 phenotype of individuals homozygous and compound heterozygous for this variant is highly specific for MPS based on null alpha-L-iduronidase activity, consistent with disease (PMID: 27146977). The presence of this variant in 3 affected homozygotes and in combination with reported pathogenic and likely pathogenic variants in 5 individuals with MPS increases the likelihood that the p.Ala75Thr variant is pathogenic (VariationID: 11908, 11909; PMID: 29843745, 27146977, 28752568). 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 other pathogenic or likely pathogenic variants in individuals with MPS and the phenotype of individuals with the variant being highly specific for MPS. ACMG/AMP Criteria applied: PM3_very-strong, PM2, PP3, PP4 (Richards 2015). -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 15, 2023	This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 75 of the IDUA protein (p.Ala75Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with mucopolysaccharidosis type I (PMID: 8680403, 11735025, 16438163, 27146977, 29843745). 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: 222993). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on IDUA protein function. Experimental studies have shown that this missense change affects IDUA function (PMID: 7550232). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

May 22, 2023

- -

Hurler syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Nov 16, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.28

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.74

Eigen

Uncertain

0.29

Eigen_PC

Uncertain

0.28

FATHMM_MKL

Benign

0.68

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.27

MetaRNN

Pathogenic

0.98

MetaSVM

Benign

-0.35

MutationAssessor

Uncertain

2.6

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-2.6

REVEL

Pathogenic

0.80

Sift

Benign

0.056

Sift4G

Uncertain

0.011

Polyphen

1.0

Vest4

0.86

MutPred

0.91

Loss of stability (P = 0.0056);

MVP

0.99

MPC

0.74

ClinPred

0.98

GERP RS

3.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.57

gMVP

0.75

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

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