ENST00000637244.1:n.*2079C>T

Variant names:

• chr8-18057161-G-A
• rs897374759
• ENST00000637244.1:n.*2079C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000637244.1(ASAH1):​n.*2079C>T variant causes a non coding transcript exon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000635 in 236,124 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 (★).

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000048 (0 hom.)
• Consequence: ASAH1 ENST00000637244.1 non_coding_transcript_exon
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.961
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.9).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASAH1	NM_177924.5	c.*373C>T		3_prime_UTR_variant	Exon 14 of 14	ENST00000637790.2	NP_808592.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASAH1	ENST00000637790.2	c.*373C>T		3_prime_UTR_variant	Exon 14 of 14	1	NM_177924.5	ENSP00000490272.1

Frequencies

GnomAD3 genomes AF: 0.0000723 AC: 11 AN: 152160 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.000162

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000476 AC: 4 AN: 83964 Hom.: 0 Cov.: 0 AF XY: 0.0000672 AC XY: 3 AN XY: 44674

African (AFR) AF: 0.00 AC: 0 AN: 3130

American (AMR) AF: 0.00 AC: 0 AN: 4250

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2048

East Asian (EAS) AF: 0.00 AC: 0 AN: 4588

South Asian (SAS) AF: 0.00 AC: 0 AN: 13884

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 3860

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 356

European-Non Finnish (NFE) AF: 0.0000843 AC: 4 AN: 47456

Other (OTH) AF: 0.00 AC: 0 AN: 4392

GnomAD4 genome AF: 0.0000723 AC: 11 AN: 152160 Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6 AN XY: 74326

African (AFR) AF: 0.00 AC: 0 AN: 41444

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10594

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000162 AC: 11 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000529

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Farber lipogranulomatosis Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.90
CADD	Benign	0.46
DANN	Benign	0.57
PhyloP100		-0.96

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: rs897374759; hg19: chr8-17914670;