chr17-7220831-G-C

Position:

• chr17-7220831-G-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2_Supporting PVS1 PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.342+1G>C variant in ACADVL occurs within the canonical splice donor site of intron 5. It is predicted to cause skipping of biologically-relevant-exon 5, resulting in a frameshift leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant is absent from gnomAD v2.1.1 (PM2_Moderate). This variant is reported in at least one patient with severe hypoglycemia and postmortem C14:1 measurement of 1.35uM (PP4, PMID:20107901). In addition, this patient carried the p.Val283Ala mutation. In summary, this variant meets the criteria to be classified as pathogenic for autosomal recessive very long chain acyl-CoA dehydrogenase (VLCAD) deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen ACADVL Variant Curation Expert Panel: PVS1, PM2_supporting, PP4_Moderate). LINK:https://erepo.genome.network/evrepo/ui/classification/CA397722627/MONDO:0008723/021

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ACADVL NM_000018.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:3
• 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 11 ACMG points.

Transcripts

RefSeq

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

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACADVL	ENST00000356839.10	c.342+1G>C		splice_donor_variant		1	NM_000018.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461744 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727154

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: reviewed by expert panel

Submissions by phenotype

Very long chain acyl-CoA dehydrogenase deficiency Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Nov 01, 2019	The NM_000018.3:c.342+1G>C (NP_000009.1:p.?) [GRCH38: NC_000017.11:g.7220831G>C] variant in ACADVL gene is interpretated to be Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID: 20107901. This variant meets the following evidence codes reported in the ACMG guidelines: PVS1, PS3 -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 14, 2023	This sequence change affects a donor splice site in intron 5 of the ACADVL 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 ACADVL are known to be pathogenic (PMID: 9973285, 11590124). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with very long chain acyl-CoA dehydrogenase deficiency (PMID: 20107901). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 474896). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, reviewed by expert panel	curation	ClinGen ACADVL Variant Curation Expert Panel, ClinGen	Feb 07, 2022	The c.342+1G>C variant in ACADVL occurs within the canonical splice donor site of intron 5. It is predicted to cause skipping of biologically-relevant-exon 5, resulting in a frameshift leading to nonsense mediated decay in a gene in which loss-of-function is an established disease mechanism (PVS1). This variant is absent from gnomAD v2.1.1 (PM2_Moderate). This variant is reported in at least one patient with severe hypoglycemia and postmortem C14:1 measurement of 1.35uM (PP4, PMID: 20107901). In addition, this patient carried the p.Val283Ala mutation. In summary, this variant meets the criteria to be classified as pathogenic for autosomal recessive very long chain acyl-CoA dehydrogenase (VLCAD) deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen ACADVL Variant Curation Expert Panel: PVS1, PM2_supporting, PP4_Moderate). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;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		0.29		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;