rs780020193

Positions:

• chr17-7220831-G-A
• chr17-7220831-G-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000018.4(ACADVL):​c.342+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: 33)
• Consequence: ACADVL NM_000018.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:1
• Conservation: PhyloP100: 8.78

Genes affected

ACADVL (HGNC:92): (acyl-CoA dehydrogenase very long chain) The protein encoded by this gene is targeted to the inner mitochondrial membrane where it catalyzes the first step of the mitochondrial fatty acid beta-oxidation pathway. This acyl-Coenzyme A dehydrogenase is specific to long-chain and very-long-chain fatty acids. A deficiency in this gene product reduces myocardial fatty acid beta-oxidation and is associated with cardiomyopathy. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 8.3, offset of 29, new splice context is: ctgGTgagg. 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 17-7220831-G-A is Pathogenic according to our data. Variant chr17-7220831-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1707705.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACADVL	NM_000018.4	c.342+1G>A		splice_donor_variant, intron_variant		ENST00000356839.10	NP_000009.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACADVL	ENST00000356839.10	c.342+1G>A		splice_donor_variant, intron_variant		1	NM_000018.4	ENSP00000349297.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251302 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135856

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: reviewed by expert panel

Submissions by phenotype

Very long chain acyl-CoA dehydrogenase deficiency Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

ClinGen ACADVL Variant Curation Expert Panel, ClinGen

Sep 23, 2022

The c.342+1G>A variant in ACADVL is a splice site variant affecting the canonical donor splice site in intron 5. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. This variant is present at low frequency (<0.1%) in population databases (ExAC). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site (Splice AI). This variant has not been reported in the literature either in functional studies or in patients with VLCAD and there is no entry in ClinVar. This variant is classified as Likely Pathogenic based on ACADVL-specific ACMG/AMP criteria PVS1 and PM2. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.30		Position offset: 28
DS_DL_spliceai		1.0		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs780020193; hg19: chr17-7124150;