rs74315472
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000487.6(ARSA):c.827C>T(p.Thr276Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000372 in 1,613,786 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_000487.6 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
ARSA | NM_000487.6 | c.827C>T | p.Thr276Met | missense_variant | Exon 4 of 8 | ENST00000216124.10 | NP_000478.3 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
ARSA | ENST00000216124.10 | c.827C>T | p.Thr276Met | missense_variant | Exon 4 of 8 | 1 | NM_000487.6 | ENSP00000216124.5 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152246Hom.: 0 Cov.: 33
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461540Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1AN XY: 727084
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152246Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74382
ClinVar
Submissions by phenotype
Metachromatic leukodystrophy Pathogenic:8Other:1
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Variant summary: The ARSA c.827C>T (p.Thr276Met) variant causes a missense change involving the alteration of a conserved nucleotide. 5/5 in silico tools predict a damaging outcome for this variant. This variant is found in the Alkaline-phosphatase-like, core domain (IPR017850). The variant of interest has been observed in a large, broad control population, ExAC, in 1/119904 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic ARSA variant (0.0027951). Multiple studies showed this variant as co-segregating with MLD in families of Lebanese and Italian origins (Harvey_1993, Bertelli_2005). In addition, low arylsulfatase A and sulfatidase activity was observed in peripheral leukocytes and cultured skin fibroblasts in patients carrying the variant. Also, multiple clinical diagnostic laboratories/reputable databases classified this variant as likely pathogenic/pathogenic. Taken together, this variant is classified as pathogenic. -
The homozygous p.Thr276Met variant (sometimes called p.Thr274Met) in ARSA was identified by our study in one individual with Metachromatic Leukodystrophy. The p.Thr276Met variant in ARSA has been reported in 18 individuals with metachromatic leukodystrophy (most of whom were Arabian or Lebanese), segregated with disease in 4 affected relatives from 2 families (PMID: 19815439, 26462614, 8104633, 7825603), and has been identified in 0.0004068% (1/245818) of chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs74315472). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported pathogenic and likely pathogenic by Invitae and others in ClinVar (Variation ID: 3075). Invitae also reported the presence of this variant in the compound heterozygous state and in an individual with metachromatic leukodystrophy, slightly increasing the likelihood that the p.Thr276Met variant is pathogenic. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In vitro functional studies provide some evidence that the p.Thr276Met variant may impact protein function by reducing or eliminating catalytic enzyme activity (PMID: 7825603, 8723680). However, these types of assays may not accurately represent biological function. In summary, the p.Thr276Met variant is pathogenic based off of our findings, multiple reports in ClinVar, and the literature. ACMG/AMP Criteria applied: PM2, PS3, PP1_Moderate, PP3, PM3_Supporting (Richards 2015). -
This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PS1,PS3,PM2,PP3. -
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This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 276 of the ARSA protein (p.Thr276Met). This variant is present in population databases (rs74315472, gnomAD no frequency). This missense change has been observed in individuals with metachromatic leukodystrophy (MLD) (PMID: 8104633, 18786133, 19815439, 26462614; internal data). It has also been observed to segregate with disease in related individuals. This variant is also known as T274M. ClinVar contains an entry for this variant (Variation ID: 3075). 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 expected to disrupt ARSA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects ARSA function (PMID: 7825603, 8723680). For these reasons, this variant has been classified as Pathogenic. -
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ARSA-related disorder Pathogenic:1
The ARSA c.827C>T variant is predicted to result in the amino acid substitution p.Thr276Met. In the literature this variant is also referred to as c.821C>T (p.Thr274Met). This variant has been reported in the compound heterozygous and homozygous states in individuals with late infantile metachromatic leukodystrophy (MLD) (Harvey et al. 1993. PubMed ID: 8104633; Family 3, Proband 4, Bertelli et al. 2006. PubMed ID: 16678723; Sample U7, Tan et al. 2009. PubMed ID: 19815439). This variant also led to decreased ARSA activity in the patients (Harvey et al. 1993. PubMed ID: 8104633; Bertelli et al. 2006. PubMed ID: 16678723; Tan et al. 2009. PubMed ID: 19815439). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as pathogenic. -
not provided Pathogenic:1
Not found in the total gnomAD dataset, and the data is high quality (0/279214 chr). Found in at least one symptomatic patient. Predicted to have a damaging effect on the protein. Damaging to protein function(s) relevant to disease mechanism. Very strong co-segregation with disease, and data include affected and unaffected individuals from multiple families. -
METACHROMATIC LEUKODYSTROPHY, SEVERE Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at