4-987092-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000203.5(IDUA):c.8C>A(p.Pro3His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000476 in 1,471,834 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. P3P) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000015 (0 hom.)
• Consequence: IDUA NM_000203.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.251

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.34957713).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IDUA	NM_000203.5	c.8C>A	p.Pro3His	missense_variant	1/14	ENST00000514224.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IDUA	ENST00000514224.2	c.8C>A	p.Pro3His	missense_variant	1/14	2	NM_000203.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152056 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000121

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000152 AC: 2 AN: 1319778 Hom.: 0 Cov.: 30 AF XY: 0.00000306 AC XY: 2 AN XY: 652546

Gnomad4 AFR exome AF: 0.0000373

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000348

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 AF: 0.0000329 AC: 5 AN: 152056 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74296

Gnomad4 AFR AF: 0.000121

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: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.0000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mucopolysaccharidosis type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 28, 2022

This sequence change replaces proline, which is neutral and non-polar, with histidine, which is basic and polar, at codon 3 of the IDUA protein (p.Pro3His). 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 variant has not been reported in the literature in individuals affected with IDUA-related conditions. 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. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Uncertain	0.072	D
BayesDel_noAF	Benign	-0.13
Cadd	Benign	11
Dann	Benign	0.71
DEOGEN2	Benign	0.24	T;.
Eigen	Benign	-0.27
Eigen_PC	Benign	-0.47
FATHMM_MKL	Benign	0.38	N
LIST_S2	Benign	0.38	T;T
M_CAP	Pathogenic	0.82	D
MetaRNN	Benign	0.35	T;T
MetaSVM	Uncertain	0.47	D
MutationAssessor	Uncertain	2.1	M;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-1.6	N;N
REVEL	Uncertain	0.31
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.98	D;.
Vest4		0.26
MutPred		0.32		Loss of catalytic residue at P3 (P = 0.0189);Loss of catalytic residue at P3 (P = 0.0189);
MVP		0.97
MPC		0.22
ClinPred		0.46	T
GERP RS		3.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.18
gMVP		0.52

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

Other links and lift over

dbSNP: rs1333424959; hg19: chr4-980880;