NM_000203.5:c.493+1G>A

Variant names:

• chr4-1000990-G-A
• rs1553916957
• NM_000203.5:c.493+1G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_000203.5(IDUA):​c.493+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (no stars). The gene IDUA is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: IDUA NM_000203.5 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.12
• 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: Myriad Women’s Health, ClinGen
• Scheie syndrome

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

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

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

ACMG classification

Specifications for IDUA are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.055045873 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-1000990-G-A is Pathogenic according to our data. Variant chr4-1000990-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 558143.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000203.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDUA	NM_000203.5	MANE Select	c.493+1G>A		splice_donor intron	N/A	NP_000194.2	P35475-1
	IDUA	NM_001363576.1		c.97+1G>A		splice_donor intron	N/A	NP_001350505.1
	IDUA	NR_110313.1		n.581+1G>A		splice_donor intron	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IDUA	ENST00000514224.2	TSL:2 MANE Select	c.493+1G>A		splice_donor intron	N/A	ENSP00000425081.2	P35475-1
	IDUA	ENST00000247933.9	TSL:1	c.493+1G>A		splice_donor intron	N/A	ENSP00000247933.4	P35475-1
	IDUA	ENST00000962389.1		c.568+1G>A		splice_donor intron	N/A	ENSP00000632448.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1454748 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 724164

African (AFR) AF: 0.00 AC: 0 AN: 33372

American (AMR) AF: 0.00 AC: 0 AN: 44696

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26086

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.00 AC: 0 AN: 86136

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1106458

Other (OTH) AF: 0.00 AC: 0 AN: 60174

GnomAD4 genome Cov.: 34

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Hurler syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	30
DANN	Uncertain	0.98
Eigen	Pathogenic	0.89
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.1
GERP RS		4.7
RBP_binding_hub_radar		1.0
RBP_regulation_power_radar		2.8
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.54		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.54		Position offset: -1

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

Other links and lift over

dbSNP: rs1553916957; hg19: chr4-994778;