NM_000203.5:c.820G>T

Variant names:

• chr4-1002009-G-T
• rs1553917192
• NM_000203.5:c.820G>T

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PVS1 PM2 PP3 PP5_Moderate

The NM_000203.5(IDUA):​c.820G>T​(p.Glu274*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. E274E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: IDUA NM_000203.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 2.51
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• mucopolysaccharidosis type 1

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health
• Scheie syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), Orphanet
• Hurler syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
• Hurler-Scheie syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 4-1002009-G-T is Pathogenic according to our data. Variant chr4-1002009-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 553227.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IDUA	NM_000203.5	c.820G>T	p.Glu274*	stop_gained	Exon 7 of 14	ENST00000514224.2	NP_000194.2
IDUA	NM_001363576.1	c.424G>T	p.Glu142*	stop_gained	Exon 6 of 13		NP_001350505.1
IDUA	XM_047415650.1	c.820G>T	p.Glu274*	stop_gained	Exon 7 of 12		XP_047271606.1
IDUA	NR_110313.1	n.908G>T		non_coding_transcript_exon_variant	Exon 7 of 14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IDUA	ENST00000514224.2	c.820G>T	p.Glu274*	stop_gained	Exon 7 of 14	2	NM_000203.5	ENSP00000425081.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1442692 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 715748

African (AFR) AF: 0.00 AC: 0 AN: 33356

American (AMR) AF: 0.00 AC: 0 AN: 41162

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25596

East Asian (EAS) AF: 0.00 AC: 0 AN: 38998

South Asian (SAS) AF: 0.00 AC: 0 AN: 83030

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50482

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5740

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1104586

Other (OTH) AF: 0.00 AC: 0 AN: 59742

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis type 1 Pathogenic:1

Dec 20, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 553227). This premature translational stop signal has been observed in individual(s) with IDUA-related conditions (PMID: 8019563). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Glu274*) 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). -

Hurler syndrome Pathogenic:1

Aug 08, 2017

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

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: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	50
DANN	Uncertain	1.0
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Benign	0.74	D
PhyloP100		2.5
Vest4		0.85
ClinPred		1.0	D
GERP RS		4.1
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.58		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.58		Position offset: 3

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

Other links and lift over

dbSNP: rs1553917192; hg19: chr4-995797;