rs104893981
Variant summary
Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PM2PP2PP3_ModeratePP5_Very_Strong
The NM_000434.4(NEU1):c.893C>T(p.Ala298Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,612,898 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000434.4 missense
Scores
Clinical Significance
Conservation
Publications
- sialidosisInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- sialidosis type 2Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
- congenital sialidosis type 2Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- juvenile sialidosis type 2Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- sialidosis type 1Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Genome browser will be placed here
ACMG classification
Our verdict: Pathogenic. The variant received 15 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152128Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000406 AC: 10AN: 246526 AF XY: 0.0000447 show subpopulations
GnomAD4 exome AF: 0.0000253 AC: 37AN: 1460770Hom.: 0 Cov.: 32 AF XY: 0.0000303 AC XY: 22AN XY: 726696 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152128Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74306 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Sialidosis type 2 Pathogenic:2
The NEU1 c.893C>T (p.Ala298Val) missense variant has been reported in two individuals with mucolipidosis, type 1, including one who carried the variant in a homozygous state and one who carried the variant in a compound heterozygous state (Lukong et al. 2000; Pattison et al. 2004). The p.Ala298Val was absent from 20 controls and is reported at a frequency of 0.00006 in the European (non-Finnish) population of the Exome Aggregation Consortium. Functional studies using COS-7 cells and sialidosis-deficient human fibroblasts demonstrated that the p.Ala298Val variant has very low sialidase activity compared to wild type NEU1, and the p.Ala298Val variant also results in aberrant localization of the NEU1 protein, likely due to protein misfolding (Lukong et al. 2000; Pattison et al. 2004). Based on the evidence, the p.Ala298Val variant is classified as likely pathogenic for mucolipidosis, type I. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
- -
not provided Pathogenic:1
This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 298 of the NEU1 protein (p.Ala298Val). This variant is present in population databases (rs104893981, gnomAD 0.07%). This missense change has been observed in individual(s) with sialidosis (PMID: 10767332, 14695530). ClinVar contains an entry for this variant (Variation ID: 2457). 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) indicates that this missense variant is not expected to disrupt NEU1 protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects NEU1 function (PMID: 10767332, 11279074, 14695530). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Sialidosis Pathogenic:1
Variant summary: NEU1 c.893C>T (p.Ala298Val) results in a non-conservative amino acid change located in the Sialidase domain (IPR011040) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 4.1e-05 in 246526 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in NEU1 causing Sialidosis (4.1e-05 vs 0.0011), allowing no conclusion about variant significance. c.893C>T has been reported in the literature in at least one homozygote and one compound heterozygote affected with Sialidosis (e.g., Lukong_2000, Pattison_2004). These data indicate that the variant is likely to be associated with disease. Several publications report experimental evidence evaluating an impact on protein function, finding that the variant results in <10% enzymatic activity, which is likely due to protein misfolding (e.g, Lukong_2000, Lukong_2001, Pattison_2004). The following publications have been ascertained in the context of this evaluation (PMID: 10767332, 11279074, 14695530). ClinVar contains an entry for this variant (Variation ID: 2457). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at