4-987098-G-GC

Position:

• chr4-987098-G-GC

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000203.5(IDUA):​c.19dup​(p.Arg7ProfsTer56) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000762 in 1,312,170 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. R5R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.6e-7 (0 hom.)
• Consequence: IDUA NM_000203.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -4.36

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 248 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-987098-G-GC is Pathogenic according to our data. Variant chr4-987098-G-GC is described in ClinVar as [Pathogenic]. Clinvar id is 2021616.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IDUA	NM_000203.5	c.19dup	p.Arg7ProfsTer56	frameshift_variant	1/14	ENST00000514224.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IDUA	ENST00000514224.2	c.19dup	p.Arg7ProfsTer56	frameshift_variant	1/14	2	NM_000203.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.62e-7 AC: 1 AN: 1312170 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 648184

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000368

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis type 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 05, 2022

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals affected with IDUA-related conditions. 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 sequence change creates a premature translational stop signal (p.Arg7Profs*56) 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). -

Computational scores

Source: dbNSFP v4.3

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr4-980886;