chr17-7222677-GAGA-G
Variant summary
Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM1PM2PM4_SupportingPP5_Very_Strong
The NM_000018.4(ACADVL):c.896_898delAGA(p.Lys299del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,613,636 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★★).
Frequency
Consequence
NM_000018.4 disruptive_inframe_deletion
Scores
Clinical Significance
Conservation
Publications
- very long chain acyl-CoA dehydrogenase deficiencyInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, ClinGen, PanelApp Australia, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 13 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| ACADVL | NM_000018.4 | c.896_898delAGA | p.Lys299del | disruptive_inframe_deletion | Exon 10 of 20 | ENST00000356839.10 | NP_000009.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| ACADVL | ENST00000356839.10 | c.896_898delAGA | p.Lys299del | disruptive_inframe_deletion | Exon 10 of 20 | 1 | NM_000018.4 | ENSP00000349297.5 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152154Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000240 AC: 6AN: 250448 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000116 AC: 17AN: 1461482Hom.: 0 AF XY: 0.0000151 AC XY: 11AN XY: 727000 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152154Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74318 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Very long chain acyl-CoA dehydrogenase deficiency Pathogenic:8
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.
The NM_000018.3:c.896_898delAGA (NP_000009.1:p.Lys299del) [GRCH38: NC_000017.11:g.7222684_7222686delAGA] variant in ACADVL gene is interpretated to be Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID: 8554073. This variant meets the following evidence codes reported in the ACMG guidelines: PVS1, PS3
The ACADVL c.896_898delAGA; p.Lys299del variant (rs398123094) has been described in individuals identified by newborn screening and in an individual described as having very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency (Lin 2020, Schiff 2013, Souri 1996). This variant is also reported in ClinVar (Variation ID: 92292). It is found in the general population with an overall allele frequency of 0.002% (7/ 281832 alleles) in the Genome Aggregation Database. This variant deletes a single lysine residue leaving the rest of the protein in-frame. The lysine at codon 299 is conserved across mammals and the loss of this codon has been shown to result in an unstable transcript (Souri 1996). Based on available information, this variant is considered to be pathogenic. References: Lin Y et al. Newborn screening and genetic characteristics of patients with short- and very long-chain acyl-CoA dehydrogenase deficiencies. Clin Chim Acta. 2020 Nov;510:285-290. PMID: 32710939. Schiff M et al. Molecular and cellular pathology of very-long-chain acyl-CoA dehydrogenase deficiency. Mol Genet Metab. 2013 May;109(1):21-7. PMID: 23480858. Souri M et al. Mutation analysis of very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency: identification and characterization of mutant VLCAD cDNAs from four patients. Am J Hum Genet. 1996 Jan;58(1):97-106. PMID: 8554073.
This variant, c.896_898del, results in the deletion of 1 amino acid(s) of the ACADVL protein (p.Lys299del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs761162357, gnomAD 0.008%). This variant has been observed in individual(s) with clinical features of very-long-chain acyl-coenzyme A dehydrogenase deficiency (PMID: 8554073, 10738914; internal data). This variant is also known as c.895_897del and K258del. ClinVar contains an entry for this variant (Variation ID: 92292). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this variant affects ACADVL function (PMID: 8554073). This variant disrupts the p.Lys299 amino acid residue in ACADVL. Other variant(s) that disrupt this residue have been observed in individuals with ACADVL-related conditions (PMID: 9973285, 16982043), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic.
Variant summary: ACADVL c.896_898delAGA (p.Lys299del) results in an in-frame deletion that is predicted to remove one amino acids from the encoded protein. The variant allele was found at a frequency of 2.4e-05 in 250448 control chromosomes (gnomAD). c.896_898delAGA (also known as c.895_897del and K258del) has been reported in the literature in multiple individuals affected with features of Very Long Chain Acyl-CoA Dehydrogenase Deficiency (examples: Souri_1996, Mathur_1999, Lin_2020, Wang_2021). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence that this variant disrupts normal protein activity (Souri_1996). The following publications have been ascertained in the context of this evaluation (PMID: 8554073, 32710939, 10077518, 33278787). Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic.
NM_000018.4(ACADVL):c.896_898del (p.Lys299del) variant in ACADVL is an in-frame deletion (removes amino acids Lys299) in exon 10/20 that is not predicted to impact splicing (SpliceAI: 0.02). The highest population minor allele frequency in gnomAD v4.1.0 is 0.00001 in Non-Finnish European population, which is lower than the ClinGen ACADVL Variant Curation Expert Panel threshold (<0.001) for PM2_Supporting, meeting this criterion (PM2_Supporting). The c.896_898del variant is predicted to cause a change in the length of the protein (p.Lys299del) due to an in-frame deletion of an amino acid in a non-repeat region (PM4). This variant is reported in the literature in multiple individuals affected with very long-chain acyl-CoA dehydrogenase deficiency in compound heterozygous fashion, with at least one of whom exhibiting reduced VLCAD enzyme levels (< 20% WT control), which is highly specific for VLCAD deficiency (PP4_Moderate, PMID:10738914). This patient also carried a likely pathogenic variant c.753-2A>C in trans (PM3 score = 1.0, PM3, PMID:10738914). Well controlled functional studies by CHO cell transfection found that both the resultant mRNA and protein were significantly unstable, resulting in pronounced reduction in VLCAD activity (PS3_Supporting, PMID:8554073). In summary, this variant meets the criteria to be classified as likely 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: PM2_Supporting, PM4, PP4_Moderate, PM3, and PS3_Supporting (ACADVL VCEP specifications version 2; approved May 01, 2025).
not provided Pathogenic:2
Reported previously in association with VLCAD deficiency in multiple individuals (Souri et al., 1996; Schiff et al., 2013; Merinero et al., 2017); Functional studies in CHO cells found that the resultant mRNA and protein were unstable, that the resultant protein appeared abnormal in dimer assembly, and was associated with undetectable activity of the VLCAD enzyme (Souri et al., 1996); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 8554073, 23480858, 28755359, 27535533, 33278787, 32710939)
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at