22-50626877-G-T

Variant names:

• chr22-50626877-G-T
• rs74315467
• NM_000487.6:c.641C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 7P and 1B. PM1 PM2 PM5 PP2 BP4

The NM_000487.6(ARSA):​c.641C>A​(p.Ala214Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,162 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A214T) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ARSA NM_000487.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.93
• Publications: 9 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 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-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 196275.
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3492895).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ARSA	NM_000487.6	c.641C>A	p.Ala214Asp	missense_variant	Exon 3 of 8	ENST00000216124.10	NP_000478.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ARSA	ENST00000216124.10	c.641C>A	p.Ala214Asp	missense_variant	Exon 3 of 8	1	NM_000487.6	ENSP00000216124.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000798 AC: 2 AN: 250702 AF XY: 0.0000147

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461162 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 726866

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52924

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111820

Other (OTH) AF: 0.00 AC: 0 AN: 60380

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Metachromatic leukodystrophy Uncertain:1

Mar 25, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

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	Pathogenic	0.84
BayesDel_addAF	Uncertain	0.081	D
BayesDel_noAF	Uncertain	0.060
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.28	T;T;T;.;T
Eigen	Benign	-0.0014
Eigen_PC	Benign	0.014
FATHMM_MKL	Benign	0.41	N
LIST_S2	Benign	0.0	.;.;.;T;T
M_CAP	Pathogenic	0.36	D
MetaRNN	Benign	0.35	T;T;T;T;T
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Benign	0.0	.;.;.;.;.
PhyloP100		2.9
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.88	N;N;N;N;N
REVEL	Uncertain	0.57
Sift	Benign	0.20	T;T;T;T;T
Sift4G	Benign	0.23	T;T;T;T;T
Vest4		0.36
ClinPred		0.40	T
GERP RS		5.4
gMVP		0.88
Mutation Taster		=9/91	disease causing

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

Other links and lift over

dbSNP: rs74315467; hg19: chr22-51065305;