chr17-42541185-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM5PP5BP4

The NM_000263.4(NAGLU):​c.1000G>A​(p.Val334Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000018 in 1,613,216 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V334F) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

NAGLU
NM_000263.4 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 5.39

Publications

8 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: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000263.4
PM5
Other missense variant is known to change same aminoacid residue: Variant chr17-42541185-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 553204.Status of the report is criteria_provided_single_submitter, 1 stars.
PP5
Variant 17-42541185-G-A is Pathogenic according to our data. Variant chr17-42541185-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 623899.
BP4
Computational evidence support a benign effect (MetaRNN=0.39786398). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NAGLUNM_000263.4 linkc.1000G>A p.Val334Ile missense_variant Exon 5 of 6 ENST00000225927.7 NP_000254.2 P54802A0A140VJE4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NAGLUENST00000225927.7 linkc.1000G>A p.Val334Ile missense_variant Exon 5 of 6 1 NM_000263.4 ENSP00000225927.1 P54802

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152162
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.000478
GnomAD2 exomes
AF:
0.0000240
AC:
6
AN:
250414
AF XY:
0.0000369
show subpopulations
Gnomad AFR exome
AF:
0.0000616
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:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000171
AC:
25
AN:
1460936
Hom.:
0
Cov.:
32
AF XY:
0.0000206
AC XY:
15
AN XY:
726810
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52480
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000162
AC:
18
AN:
1112004
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
2
4
7
9
11
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:
0.0000263
AC:
4
AN:
152280
Hom.:
0
Cov.:
31
AF XY:
0.0000269
AC XY:
2
AN XY:
74462
show subpopulations
African (AFR)
AF:
0.0000722
AC:
3
AN:
41546
American (AMR)
AF:
0.00
AC:
0
AN:
15296
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.000473
AC:
1
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000770
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Tip-toe gait Pathogenic:1
May 02, 2018
Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Hereditary motor sensory neuropathy (HMSN), also known as Charcot-Marie-Tooth Disease (CMT), is the most commonly inherited peripheral polyneuropathy. It constitutes a group of inherited, progressive, motor and sensory peripheral nerve disorders with properties of demyelination, axonal degeneration, or both. It is classified by clinical characteristics, modes of inheritance, electrophysiologic features, metabolic defects, and specific gene markers. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -

not provided Uncertain:1
Apr 01, 2018
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mucopolysaccharidosis, MPS-III-B;C5569050:Charcot-Marie-Tooth disease axonal type 2V Uncertain:1
Jul 23, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 334 of the NAGLU protein (p.Val334Ile). This variant is present in population databases (rs749140168, gnomAD 0.01%). This missense change has been observed in individual(s) with mucopolysaccarhidosis type IIIB (PMID: 33747789). ClinVar contains an entry for this variant (Variation ID: 623899). 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 not expected to disrupt NAGLU protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on NAGLU function (PMID: 29979746). This variant disrupts the p.Val334 amino acid residue in NAGLU. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10094189; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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
0.080
BayesDel_addAF
Benign
-0.071
T
BayesDel_noAF
Benign
-0.16
CADD
Benign
19
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.61
D
Eigen
Benign
-0.10
Eigen_PC
Benign
-0.0051
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Benign
0.66
T
M_CAP
Uncertain
0.13
D
MetaRNN
Benign
0.40
T
MetaSVM
Uncertain
0.71
D
MutationAssessor
Benign
1.2
L
PhyloP100
5.4
PrimateAI
Benign
0.46
T
PROVEAN
Benign
-0.25
N
REVEL
Uncertain
0.43
Sift
Benign
0.49
T
Sift4G
Benign
0.68
T
Polyphen
0.80
P
Vest4
0.23
MVP
0.55
MPC
0.57
ClinPred
0.11
T
GERP RS
4.1
PromoterAI
-0.020
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.10
gMVP
0.63
Mutation Taster
=88/12
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: rs749140168; hg19: chr17-40693203; COSMIC: COSV56795547; COSMIC: COSV56795547; API