chr22-50626878-C-T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 8P and 1B. PM1PM2PM5PP2PP5BP4

The NM_000487.6(ARSA):​c.640G>A​(p.Ala214Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,262 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. A214P) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

ARSA
NM_000487.6 missense

Scores

2
5
11

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:2

Conservation

PhyloP100: 2.73

Publications

8 publications found
Variant links:
Genes affected
ARSA (HGNC:713): (arylsulfatase A) The protein encoded by this gene hydrolyzes cerebroside sulfate to cerebroside and sulfate. Defects in this gene lead to metachromatic leucodystrophy (MLD), a progressive demyelination disease which results in a variety of neurological symptoms and ultimately death. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Dec 2010]
ARSA Gene-Disease associations (from GenCC):
  • metachromatic leukodystrophy
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, ClinGen
  • metachromatic leukodystrophy, juvenile form
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 16 uncertain in NM_000487.6
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr22-50626878-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 68145.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 159 curated pathogenic missense variants (we use a threshold of 10). The gene has 11 curated benign missense variants. Gene score misZ: 0.38013 (below the threshold of 3.09). Trascript score misZ: -0.56919 (below the threshold of 3.09). GenCC associations: The gene is linked to metachromatic leukodystrophy, juvenile form, metachromatic leukodystrophy.
PP5
Variant 22-50626878-C-T is Pathogenic according to our data. Variant chr22-50626878-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 196275.
BP4
Computational evidence support a benign effect (MetaRNN=0.3077898). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ARSANM_000487.6 linkc.640G>A p.Ala214Thr missense_variant Exon 3 of 8 ENST00000216124.10 NP_000478.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ARSAENST00000216124.10 linkc.640G>A p.Ala214Thr missense_variant Exon 3 of 8 1 NM_000487.6 ENSP00000216124.5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152154
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
GnomAD2 exomes
AF:
0.00000798
AC:
2
AN:
250630
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.00000884
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000411
AC:
6
AN:
1461108
Hom.:
0
Cov.:
33
AF XY:
0.00000688
AC XY:
5
AN XY:
726834
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86248
European-Finnish (FIN)
AF:
0.0000189
AC:
1
AN:
52904
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111796
Other (OTH)
AF:
0.00
AC:
0
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.00000657
AC:
1
AN:
152154
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74316
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000712
Hom.:
0
Bravo
AF:
0.00000756
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:3Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Metachromatic leukodystrophy Pathogenic:3
Aug 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 214 of the ARSA protein (p.Ala214Thr). This variant is present in population databases (rs199476341, gnomAD 0.003%). This missense change has been observed in individual(s) with metachromatic leukodystrophy (PMID: 30057904). ClinVar contains an entry for this variant (Variation ID: 196275). 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 expected to disrupt ARSA protein function with a positive predictive value of 95%. This variant disrupts the p.Ala214 amino acid residue in ARSA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7906588, 9090526, 9192271, 14517960). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Sep 20, 2024
Genetics Department, Hospital Ramon y Cajal-IRYCIS
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

Variant c.640G>A (p.Ala214Thr) was evaluated according to ACMG/AMP guidelines and classified as likely pathogenic : PM1, PM2, PM5. The variant is located in a mutational hotspot without benign variation (PM1), it was identified at very low frequency in the gnomAD or 1000 Genome databases (PM2). The variant also is a novel missense change at an amino acid residue where a different pathogenic missense change has been reported (ClinVar variant RCV001380269.7). In addition, it has been previously reported as pathogenic in trans with another pathogenic allele, c.893G>T (p.Gly298Val) (PMID:30057904). -

Jun 13, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ARSA c.640G>A (p.Ala214Thr) results in a non-conservative amino acid change located in the sulfatase, N-terminal domain (IPR000917) of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 250630 control chromosomes. c.640G>A has been reported in the literature in the compound heterozygous state in individuals affected with Metachromatic Leukodystrophy (e.g. Chen_2018, Santhanakumaran_2022). These data indicate that the variant may be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.641C>T, p.Ala214Val), supporting the critical relevance of codon 214 to ARSA protein function. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 30057904, 36240581). ClinVar contains an entry for this variant (Variation ID: 196275). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Uncertain:2
Sep 13, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Reported in a patient with metachromatic leukodystrophy who also harbors a missense variant on the opposite allele (in trans) (Chen et al., 2018); In silico analysis supports that this missense variant does not alter protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 30057904) -

Oct 27, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.27
BayesDel_addAF
Uncertain
0.11
D
BayesDel_noAF
Uncertain
0.020
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Benign
0.26
T;T;T;.;T
Eigen
Benign
-0.17
Eigen_PC
Benign
-0.12
FATHMM_MKL
Benign
0.54
D
LIST_S2
Benign
0.75
.;.;.;T;T
M_CAP
Pathogenic
0.36
D
MetaRNN
Benign
0.31
T;T;T;T;T
MetaSVM
Pathogenic
0.89
D
PhyloP100
2.7
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
-0.45
N;N;N;N;N
REVEL
Uncertain
0.52
Sift
Benign
0.34
T;T;T;T;T
Sift4G
Benign
0.50
T;T;T;T;T
Vest4
0.36
MVP
0.95
ClinPred
0.27
T
GERP RS
5.4
gMVP
0.67
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs199476341; hg19: chr22-51065306; API