rs1052471595
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_000263.4(NAGLU):c.934G>A(p.Asp312Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000372 in 1,613,902 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000263.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
NAGLU | NM_000263.4 | c.934G>A | p.Asp312Asn | missense_variant | Exon 5 of 6 | ENST00000225927.7 | NP_000254.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152118Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251390Hom.: 0 AF XY: 0.00000736 AC XY: 1AN XY: 135874
GnomAD4 exome AF: 0.0000404 AC: 59AN: 1461784Hom.: 0 Cov.: 32 AF XY: 0.0000481 AC XY: 35AN XY: 727206
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152118Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 74296
ClinVar
Submissions by phenotype
Mucopolysaccharidosis, MPS-III-B Pathogenic:4Uncertain:2
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Variant summary: NAGLU c.934G>A (p.Asp312Asn) results in a conservative amino acid change located in the Alpha-N-acetylglucosaminidase, tim-barrel domain (IPR024733) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251390 control chromosomes. c.934G>A has been reported in the literature as homozygous and compound heterozygous genotypes in multiple individuals affected with Mucopolysaccharidosis Type IIIB (Sanfilippo Syndrome B) (example, Heron_2010, Yassaee_2017, Ozkinay_2021). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no variant specific experimental evidence demonstrating an impact on protein function has been reported. Although some patients ascertained above were reported as having decreased alpha-N-acetylglucosaminidase enzyme activity without presenting the primary data (example, Ozkinay_2021). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments (Pathogenic/Likely Pathogenic, n=4; VUS, n=2). Based on the evidence outlined above, the variant was classified as pathogenic. -
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.92 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.87 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000437446 /PMID: 21204211). Different missense changes at the same codon (p.Asp312Ala, p.Asp312His) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV002021561, VCV002048997). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Mucopolysaccharidosis, MPS-III-B;C5569050:Charcot-Marie-Tooth disease axonal type 2V Pathogenic:2
This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 312 of the NAGLU protein (p.Asp312Asn). This variant is present in population databases (no rsID available, gnomAD 0.003%). This missense change has been observed in individuals with Mucopolysaccharidosis type III and/or NAGLU-related conditions (PMID: 21204211, 28844463, 29269699, 31969655, 32883051, 33747789, 34396902). ClinVar contains an entry for this variant (Variation ID: 437446). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on NAGLU protein function. For these reasons, this variant has been classified as Pathogenic. -
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Inborn genetic diseases Pathogenic:1
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Tip-toe gait Pathogenic:1
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 Pathogenic:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 25525159, 28844463, 21204211, 34426522, 34396902, 32883051, 31969655, 29269699, 33747789) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at