8-18062278-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_177924.5(ASAH1):​c.648+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ASAH1
NM_177924.5 splice_donor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.57
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 7.1, offset of 31, new splice context is: cagGTagcc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-18062278-C-T is Pathogenic according to our data. Variant chr8-18062278-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1524682.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ASAH1NM_177924.5 linkc.648+1G>A splice_donor_variant, intron_variant Intron 8 of 13 ENST00000637790.2 NP_808592.2 Q13510-1Q53H01A8K0B6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASAH1ENST00000637790.2 linkc.648+1G>A splice_donor_variant, intron_variant Intron 8 of 13 1 NM_177924.5 ENSP00000490272.1 Q13510-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461856
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727224
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000756

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 01, 2022In 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 1524682). This variant has not been reported in the literature in individuals affected with ASAH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 8 of the ASAH1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ASAH1 are known to be pathogenic (PMID: 24164096, 24355074). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.43
CADD
Pathogenic
34
DANN
Uncertain
0.99
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.97
D
GERP RS
5.4

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
0.91
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.35
Position offset: -30
DS_DL_spliceai
0.91
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1411267767; hg19: chr8-17919787; API