rs137853593

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2PM5PP3_Strong

The NM_177924.5(ASAH1):​c.665C>T​(p.Thr222Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000127 in 1,579,358 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T222K) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 7.0e-7 ( 0 hom. )

Consequence

ASAH1
NM_177924.5 missense

Scores

10
4
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.45

Publications

8 publications found
Variant links:
Genes affected
ASAH1 (HGNC:735): (N-acylsphingosine amidohydrolase 1) This gene encodes a member of the acid ceramidase family of proteins. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed. Processing of this preproprotein generates alpha and beta subunits that heterodimerize to form the mature lysosomal enzyme, which catalyzes the degradation of ceramide into sphingosine and free fatty acid. This enzyme is overexpressed in multiple human cancers and may play a role in cancer progression. Mutations in this gene are associated with the lysosomal storage disorder, Farber lipogranulomatosis, and a neuromuscular disorder, spinal muscular atrophy with progressive myoclonic epilepsy. [provided by RefSeq, Oct 2015]
ASAH1 Gene-Disease associations (from GenCC):
  • ASAH1-related sphingolipidosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Farber lipogranulomatosis
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • spinal muscular atrophy-progressive myoclonic epilepsy syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp, G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr8-18061724-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 91.Status of the report is no_assertion_criteria_provided, 0 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.949

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ASAH1NM_177924.5 linkc.665C>T p.Thr222Ile missense_variant Exon 9 of 14 ENST00000637790.2 NP_808592.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASAH1ENST00000637790.2 linkc.665C>T p.Thr222Ile missense_variant Exon 9 of 14 1 NM_177924.5 ENSP00000490272.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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
GnomAD4 exome
AF:
7.01e-7
AC:
1
AN:
1427166
Hom.:
0
Cov.:
31
AF XY:
0.00000142
AC XY:
1
AN XY:
706674
show subpopulations
African (AFR)
AF:
0.0000308
AC:
1
AN:
32496
American (AMR)
AF:
0.00
AC:
0
AN:
40538
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25556
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37954
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81776
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51316
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5722
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1092730
Other (OTH)
AF:
0.00
AC:
0
AN:
59078
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74360
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.0000654
AC:
1
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Uncertain:1
Nov 21, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 222 of the ASAH1 protein (p.Thr222Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ASAH1-related conditions. ClinVar contains an entry for this variant (Variation ID: 2055731). 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 ASAH1 protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.96
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
D;D;D;.;T;T;T;T;T;T;T;.;.;.;T
Eigen
Pathogenic
0.79
Eigen_PC
Pathogenic
0.67
LIST_S2
Benign
0.0
.;D;D;D;D;.;D;D;D;D;D;D;D;D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.95
D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.70
D
MutationAssessor
Pathogenic
3.1
M;M;.;.;.;.;.;.;.;.;.;.;.;.;.
PhyloP100
8.4
PrimateAI
Uncertain
0.57
T
PROVEAN
Benign
0.0
.;D;D;D;.;.;.;.;.;.;.;.;.;D;.
Sift
Pathogenic
0.0
.;D;D;D;.;.;.;.;.;.;.;.;.;D;.
Sift4G
Pathogenic
0.0
.;D;D;D;.;.;.;.;.;.;.;.;.;D;.
Vest4
0.0
ClinPred
1.0
D
GERP RS
5.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.77
gMVP
0.97
Mutation Taster
=16/84
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: rs137853593; hg19: chr8-17919233; API