rs1401818080

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP3_ModeratePP5

The NM_152419.3(HGSNAT):​c.1542+4dupA variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000169 in 1,596,544 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

HGSNAT
NM_152419.3 splice_region, intron

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2

Conservation

PhyloP100: 2.66

Publications

1 publications found
Variant links:
Genes affected
HGSNAT (HGNC:26527): (heparan-alpha-glucosaminide N-acetyltransferase) This gene encodes a lysosomal acetyltransferase, which is one of several enzymes involved in the lysosomal degradation of heparin sulfate. Mutations in this gene are associated with Sanfilippo syndrome C, one type of the lysosomal storage disease mucopolysaccaridosis III, which results from impaired degradation of heparan sulfate. [provided by RefSeq, Jan 2009]
HGSNAT Gene-Disease associations (from GenCC):
  • mucopolysaccharidosis type 3
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • mucopolysaccharidosis type 3C
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Genomics England PanelApp, Ambry Genetics, G2P
  • retinitis pigmentosa 73
    Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • retinitis pigmentosa
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 8-43197027-T-TA is Pathogenic according to our data. Variant chr8-43197027-T-TA is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 438150.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HGSNATNM_152419.3 linkc.1542+4dupA splice_region_variant, intron_variant Intron 15 of 17 ENST00000379644.9 NP_689632.2 Q68CP4-2Q8IVU6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HGSNATENST00000379644.9 linkc.1542+4dupA splice_region_variant, intron_variant Intron 15 of 17 2 NM_152419.3 ENSP00000368965.4 Q68CP4-2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152172
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000121
AC:
3
AN:
247810
AF XY:
0.0000149
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000267
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000173
AC:
25
AN:
1444372
Hom.:
0
Cov.:
26
AF XY:
0.0000125
AC XY:
9
AN XY:
719662
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33134
American (AMR)
AF:
0.00
AC:
0
AN:
44620
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26010
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39606
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85676
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53372
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5740
European-Non Finnish (NFE)
AF:
0.0000201
AC:
22
AN:
1096410
Other (OTH)
AF:
0.0000502
AC:
3
AN:
59804
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000131
AC:
2
AN:
152172
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41430
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000508
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-C Uncertain:2
Apr 01, 2021
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Nov 10, 2021
Myriad Genetics, Inc.
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

NM_152419.2(HGSNAT):c.1542+4dupA is an intronic variant classified as a variant of uncertain significance in the context of mucopolysaccharidosis type IIIC. c.1542+4dupA has been observed in cases with relevant disease (PMID: 19479962, 25491247). Functional assessments of this variant are available in the literature (PMID: 25491247). c.1542+4dupA has been observed in population frequency databases (gnomAD: NFE 0.004%). In summary, there is insufficient evidence to classify NM_152419.2(HGSNAT):c.1542+4dupA as pathogenic or benign. Please note: this variant was assessed in the context of healthy population screening. -

Mucopolysaccharidosis, MPS-III-C;C4225287:Retinitis pigmentosa 73 Pathogenic:1
Jun 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 15 of the HGSNAT gene. It does not directly change the encoded amino acid sequence of the HGSNAT protein. RNA analysis indicates that this variant induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (no rsID available, gnomAD 0.002%). This variant has been observed in individual(s) with mucopolysaccharidosis type IIIC (PMID: 19479962, 25491247). ClinVar contains an entry for this variant (Variation ID: 438150). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 15, but is expected to preserve the integrity of the reading-frame (PMID: 25491247). This variant disrupts a region of the HGSNAT protein in which other variant(s) (p.Ala489Glu) have been determined to be pathogenic (PMID: 19479962, 19823584, 20583299, 31228227). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Retinal dystrophy Pathogenic:1
Jan 01, 2015
NIHR Bioresource Rare Diseases, University of Cambridge
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
2.7
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.95
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.37
Position offset: 2
DS_DL_spliceai
0.95
Position offset: -2

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

Publications

Other links and lift over

dbSNP: rs1401818080; hg19: chr8-43052170; API