rs398123095
Variant summary
Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong
The NM_000018.4(ACADVL):c.950T>C(p.Val317Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000031 in 1,613,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V317M) has been classified as Uncertain significance.
Frequency
Consequence
NM_000018.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 8 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152038Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251278Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135854
GnomAD4 exome AF: 0.0000335 AC: 49AN: 1461842Hom.: 0 Cov.: 32 AF XY: 0.0000344 AC XY: 25AN XY: 727224
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152038Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74258
ClinVar
Submissions by phenotype
Very long chain acyl-CoA dehydrogenase deficiency Uncertain:5
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The NM_000018.3:c.950T>C (NP_000009.1:p.Val317Ala) [GRCH38: NC_000017.11:g.7222738T>C] variant in ACADVL gene is interpretated to be Uncertain Significance based on ACMG guidelines (PMID: 25741868). This variant has been reported. This variant meets the following evidence codes reported in the ACMG guidelines: PP3 -
This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 317 of the ACADVL protein (p.Val317Ala). This variant is present in population databases (rs398123095, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of very long-chain acyl CoA dehydrogenase deficiency (PMID: 8845838, 32778825; internal data). This variant is also known as p.V277A. ClinVar contains an entry for this variant (Variation ID: 92293). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ACADVL protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
The c.950T>C; p.Val317Ala variant (rs398123095), also known as Val277Ala, has been reported in a patient with VLCAD deficiency, but its clinical significance could not be ascertained (Andresen 1996, Evans 2016). This variant is reported in ClinVar (Variation ID: 92293). This variant is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. The valine at residue 317 is highly conserved, and computational analyses predict that this variant is deleterious (REVEL: 0.968). However, given the lack of clinical and functional data, the significance of the p.Val317Ala variant is uncertain at this time. References: Andresen BS et al. Cloning and characterization of human very-long-chain acyl-CoA dehydrogenase cDNA, chromosomal assignment of the gene and identification in four patients of nine different mutations within the VLCAD gene. Hum Mol Genet. 1996 Apr;5(4):461-72. PMID: 8845838. Evans M et al. VLCAD deficiency: Follow-up and outcome of patients diagnosed through newborn screening in Victoria. Mol Genet Metab. 2016 Aug;118(4):282-7. PMID: 27246109. -
not provided Uncertain:2
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 27246109, 27209629, 32778825, 8845838, 40215729, 40149952) -
not specified Uncertain:1
Variant summary: ACADVL c.950T>C (p.Val317Ala), also referred to as p.V277A in the literature, results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251278 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.950T>C has been reported in the literature in individuals affected with Very Long Chain Acyl-CoA Dehydrogenase Deficiency, however in most cases it has been found in cis with either a pathogenic (c.848T>C, p.Val283Ala) or likely pathogenic (c.1097G>A, p.Arg366His) variant, providing supporting evidence for a benign role (e.g. Andersen_1996, Andersen_1999, Evans_2016, Adhikari_2020). Therefore, these reports do not provide unequivocal conclusions about association of the variant with Very Long Chain Acyl-CoA Dehydrogenase Deficiency. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at