rs1555621442

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000263.4(NAGLU):​c.217_221dupGCGCG​(p.Val75ArgfsTer49) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000188 in 1,064,384 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. R74R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000019 ( 0 hom. )

Consequence

NAGLU
NM_000263.4 frameshift

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 1.55

Publications

3 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 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 17-42536480-G-GGCGGC is Pathogenic according to our data. Variant chr17-42536480-G-GGCGGC is described in ClinVar as Pathogenic. ClinVar VariationId is 556349.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.217_221dupGCGCG p.Val75ArgfsTer49 frameshift_variant Exon 1 of 6 ENST00000225927.7 NP_000254.2 P54802A0A140VJE4
NAGLUXM_024450771.2 linkc.217_221dupGCGCG p.Val75ArgfsTer49 frameshift_variant Exon 1 of 7 XP_024306539.1
NAGLUXM_047436138.1 linkc.-245_-241dupGCGCG 5_prime_UTR_variant Exon 1 of 5 XP_047292094.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NAGLUENST00000225927.7 linkc.217_221dupGCGCG p.Val75ArgfsTer49 frameshift_variant Exon 1 of 6 1 NM_000263.4 ENSP00000225927.1 P54802
NAGLUENST00000586516.5 linkc.-44_-43insGCGGC upstream_gene_variant 2 ENSP00000467135.1 K7ENX5
NAGLUENST00000591587.1 linkc.-50_-49insGCGGC upstream_gene_variant 5 ENSP00000467836.1 K7EQH9
ENSG00000266929ENST00000585572.1 linkn.-30_-29insGCGGC upstream_gene_variant 4

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000188
AC:
2
AN:
1064384
Hom.:
0
Cov.:
30
AF XY:
0.00000392
AC XY:
2
AN XY:
510232
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000470
AC:
1
AN:
21288
American (AMR)
AF:
0.00
AC:
0
AN:
7960
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
13374
East Asian (EAS)
AF:
0.00
AC:
0
AN:
21400
South Asian (SAS)
AF:
0.00
AC:
0
AN:
24666
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
20244
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
2866
European-Non Finnish (NFE)
AF:
0.00000110
AC:
1
AN:
911388
Other (OTH)
AF:
0.00
AC:
0
AN:
41198
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.250
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0

ClinVar

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

Submissions by phenotype

not provided Pathogenic:3
Sep 30, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 10094189, 20852935) -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, Amsterdam University Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Mucopolysaccharidosis, MPS-III-B Pathogenic:1
Jan 30, 2018
Counsyl
Significance: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:1
Dec 25, 2023
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.Val75Argfs*49) in the NAGLU gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NAGLU are known to be pathogenic (PMID: 9832037, 10094189, 16151907). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with mucopolysaccharidosis type IIIB (MPS IIIB) (PMID: 10094189, 20852935). This variant is also known as ins5bp209. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
1.5
Mutation Taster
=4/196
disease causing (ClinVar)

Splicing

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

Publications

Other links and lift over

dbSNP: rs1555621442; hg19: chr17-40688498; API