rs58037052

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 4P and 20B. PM1PM5BP4_StrongBP6_Very_StrongBS1BS2

The NM_000203.5(IDUA):​c.235G>A​(p.Ala79Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00158 in 1,611,212 control chromosomes in the GnomAD database, including 30 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign,other (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A79V) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0085 ( 15 hom., cov: 33)
Exomes 𝑓: 0.00087 ( 15 hom. )

Consequence

IDUA
NM_000203.5 missense

Scores

8
10

Clinical Significance

Benign/Likely benign; other criteria provided, multiple submitters, no conflicts U:1B:9O:3

Conservation

PhyloP100: 4.29

Publications

21 publications found
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]
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 Gene-Disease associations (from GenCC):
  • nephrolithiasis susceptibility caused by SLC26A1
    Inheritance: AR Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -16 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_000203.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr4-987886-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1458769.Status of the report is reviewed_by_expert_panel, 3 stars.
BP4
Computational evidence support a benign effect (MetaRNN=0.0113580525).
BP6
Variant 4-987885-G-A is Benign according to our data. Variant chr4-987885-G-A is described in ClinVar as Benign/Likely_benign|other. ClinVar VariationId is 195038.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00846 (1289/152316) while in subpopulation AFR AF = 0.0299 (1242/41562). AF 95% confidence interval is 0.0285. There are 15 homozygotes in GnomAd4. There are 620 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 15 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IDUANM_000203.5 linkc.235G>A p.Ala79Thr missense_variant Exon 2 of 14 ENST00000514224.2 NP_000194.2 P35475-1
SLC26A1NM_022042.4 linkc.*948C>T 3_prime_UTR_variant Exon 3 of 3 ENST00000398516.3 NP_071325.2 Q9H2B4-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IDUAENST00000514224.2 linkc.235G>A p.Ala79Thr missense_variant Exon 2 of 14 2 NM_000203.5 ENSP00000425081.2 P35475-1
SLC26A1ENST00000398516.3 linkc.*948C>T 3_prime_UTR_variant Exon 3 of 3 1 NM_022042.4 ENSP00000381528.2 Q9H2B4-1

Frequencies

GnomAD3 genomes
AF:
0.00848
AC:
1291
AN:
152198
Hom.:
15
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0300
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00229
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:
0.0000882
Gnomad OTH
AF:
0.00287
GnomAD2 exomes
AF:
0.00239
AC:
572
AN:
239166
AF XY:
0.00173
show subpopulations
Gnomad AFR exome
AF:
0.0325
Gnomad AMR exome
AF:
0.00164
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000856
Gnomad OTH exome
AF:
0.000850
GnomAD4 exome
AF:
0.000866
AC:
1263
AN:
1458896
Hom.:
15
Cov.:
30
AF XY:
0.000733
AC XY:
532
AN XY:
725620
show subpopulations
African (AFR)
AF:
0.0314
AC:
1050
AN:
33440
American (AMR)
AF:
0.00146
AC:
65
AN:
44532
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26088
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39642
South Asian (SAS)
AF:
0.0000931
AC:
8
AN:
85952
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51828
Middle Eastern (MID)
AF:
0.00139
AC:
8
AN:
5746
European-Non Finnish (NFE)
AF:
0.0000288
AC:
32
AN:
1111380
Other (OTH)
AF:
0.00164
AC:
99
AN:
60288
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
85
170
254
339
424
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
32
64
96
128
160
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00846
AC:
1289
AN:
152316
Hom.:
15
Cov.:
33
AF XY:
0.00832
AC XY:
620
AN XY:
74490
show subpopulations
African (AFR)
AF:
0.0299
AC:
1242
AN:
41562
American (AMR)
AF:
0.00229
AC:
35
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68022
Other (OTH)
AF:
0.00284
AC:
6
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
65
130
195
260
325
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
20
40
60
80
100
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00275
Hom.:
5
Bravo
AF:
0.00964
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.0285
AC:
125
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00285
AC:
344
Asia WGS
AF:
0.00144
AC:
7
AN:
3478

ClinVar

Significance: Benign/Likely benign; other
Submissions summary: Uncertain:1Benign:9Other:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:4Other:1
Jul 27, 2016
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

May 25, 2018
Eurofins Ntd Llc (ga)
Significance:other
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- Variant classified as "other reportable" ??? variant is clinically benign (not associated with disease) but is reported when observed (e.g. pseudodeficiency alleles).

Jan 27, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Sep 18, 2018
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 27939258) -

Mucopolysaccharidosis type 1 Benign:1Other:2
-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

Pseudodeficiency variants -

Apr 28, 2017
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -

Dec 26, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:other
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- pseudodeficiency allele

not specified Benign:2
-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Nov 01, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: IDUA c.235G>A (p.Ala79Thr) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0031 in 270526 control chromosomes, predominantly at a frequency of 0.031 within the African or African-American subpopulation in the gnomAD database, including 9 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 12 fold of the estimated maximal expected allele frequency for a pathogenic variant in IDUA causing Mucopolysaccharidosis Type 1 phenotype (0.0027), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. The variant, c.235G>A, also has been reported in the literature as a well-known pseudodeficiency allele, prevalent in the African American subpopulation. Individuals with pseudodeficiency allele(s) exhibit decreased alpha-L-iduronidase enzyme activity in biochemical assays using artificial substrates, but otherwise show no evidence of disease (see e.g. in Clarke_2016). Seven ClinVar submitters (evaluation after 2014) cite the variant as benign/likely benign pseudodeficiency allele (n=6) or VUS (n=1). Based on the evidence outlined above, the variant was classified as benign. -

Hurler syndrome Benign:1
May 16, 2018
Counsyl
Significance:Likely benign
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. -

Calcium oxalate urolithiasis Benign:1
Jul 19, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.31
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Uncertain
-0.040
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
D
Eigen
Benign
0.087
Eigen_PC
Benign
0.026
FATHMM_MKL
Benign
0.52
D
LIST_S2
Uncertain
0.90
D
MetaRNN
Benign
0.011
T
MetaSVM
Benign
-0.85
T
MutationAssessor
Uncertain
2.5
M
PhyloP100
4.3
PrimateAI
Benign
0.41
T
PROVEAN
Benign
-0.84
N
REVEL
Uncertain
0.53
Sift
Uncertain
0.013
D
Sift4G
Uncertain
0.018
D
Polyphen
0.99
D
Vest4
0.75
MVP
0.98
MPC
0.74
ClinPred
0.023
T
GERP RS
2.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.20
gMVP
0.84
Mutation Taster
=94/6
polymorphism

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

Other links and lift over

dbSNP: rs58037052; hg19: chr4-981673; API