rs778021009

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_000263.4(NAGLU):​c.1447dupT​(p.Tyr483LeufsTer33) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000338 in 1,599,028 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000036 ( 0 hom. )

Consequence

NAGLU
NM_000263.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 7.57

Publications

1 publications found
Variant links:
Genes affected
NAGLU (HGNC:7632): (N-acetyl-alpha-glucosaminidase) This gene encodes an enzyme that degrades heparan sulfate by hydrolysis of terminal N-acetyl-D-glucosamine residues in N-acetyl-alpha-D-glucosaminides. Defects in this gene are the cause of mucopolysaccharidosis type IIIB (MPS-IIIB), also known as Sanfilippo syndrome B. This disease is characterized by the lysosomal accumulation and urinary excretion of heparan sulfate. [provided by RefSeq, Jul 2008]
NAGLU Gene-Disease associations (from GenCC):
  • mucopolysaccharidosis type 3B
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet, Myriad Women’s Health
  • Charcot-Marie-Tooth disease axonal type 2V
    Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 83 pathogenic variants in the truncated region.
PP5
Variant 17-42543452-G-GT is Pathogenic according to our data. Variant chr17-42543452-G-GT is described in ClinVar as Pathogenic. ClinVar VariationId is 557862.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NAGLUNM_000263.4 linkc.1447dupT p.Tyr483LeufsTer33 frameshift_variant Exon 6 of 6 ENST00000225927.7 NP_000254.2 P54802A0A140VJE4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NAGLUENST00000225927.7 linkc.1447dupT p.Tyr483LeufsTer33 frameshift_variant Exon 6 of 6 1 NM_000263.4 ENSP00000225927.1 P54802
NAGLUENST00000591587.1 linkc.*416dupT 3_prime_UTR_variant Exon 4 of 4 5 ENSP00000467836.1 K7EQH9
NAGLUENST00000592454.1 linkc.*290dupT 3_prime_UTR_variant Exon 2 of 2 2 ENSP00000468665.1 K7ESD7
ENSG00000266929ENST00000585572.1 linkn.379+4698dupT intron_variant Intron 3 of 4 4

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152284
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000450
AC:
1
AN:
222278
AF XY:
0.00000826
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:
0.0000100
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000359
AC:
52
AN:
1446744
Hom.:
0
Cov.:
32
AF XY:
0.0000431
AC XY:
31
AN XY:
719030
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33240
American (AMR)
AF:
0.00
AC:
0
AN:
42730
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25866
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39032
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84766
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49132
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.0000461
AC:
51
AN:
1106402
Other (OTH)
AF:
0.0000167
AC:
1
AN:
59822
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
3
7
10
14
17
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
152284
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74398
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41476
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68054
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-B Pathogenic:3
Nov 06, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: NAGLU c.1447dupT (p.Tyr483LeufsX33) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 4.5e-06 in 222278 control chromosomes. c.1447dupT has been reported in the literature in individuals affected with Mucopolysaccharidosis Type IIIB (Sanfilippo Syndrome B; e.g. Beesley_1998, Truxal_2016). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence that cells expressing the variant had no detectable enzyme activity in-vitro (e.g. Clark_2018). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories cited the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Jan 10, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Apr 13, 2018
Counsyl
Significance:Likely pathogenic
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. -

Mucopolysaccharidosis, MPS-III-B;C5569050:Charcot-Marie-Tooth disease axonal type 2V Pathogenic:2
Jun 24, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Tyr483Leufs*33) in the NAGLU gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 261 amino acid(s) of the NAGLU protein. This variant is present in population databases (rs778021009, gnomAD 0.001%). This premature translational stop signal has been observed in individuals with mucopolysaccharidosis type IIIB (PMID: 9832037, 27590925). ClinVar contains an entry for this variant (Variation ID: 557862). This variant disrupts a region of the NAGLU protein in which other variant(s) (p.Arg533*) have been determined to be pathogenic (PMID: 18218046). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
7.6
Mutation Taster
=1/199
disease causing (ClinVar)

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: rs778021009; hg19: chr17-40695470; API