Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000016.6(ACADM):c.882_883delAG(p.Arg294SerfsTer4) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
ACADM (HGNC:89): (acyl-CoA dehydrogenase medium chain) This gene encodes the medium-chain specific (C4 to C12 straight chain) acyl-Coenzyme A dehydrogenase. The homotetramer enzyme catalyzes the initial step of the mitochondrial fatty acid beta-oxidation pathway. Defects in this gene cause medium-chain acyl-CoA dehydrogenase deficiency, a disease characterized by hepatic dysfunction, fasting hypoglycemia, and encephalopathy, which can result in infantile death. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-75750480-AAG-A is Pathogenic according to our data. Variant chr1-75750480-AAG-A is described in ClinVar as [Pathogenic]. Clinvar id is 203549.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.882_883delAG mutation in the ACADM gene causes a frameshift starting with codon Arginine 294, changes this amino acid to a Serine residue and creates a premature Stop codon at position 4 of the new reading frame, denoted p.Arg294SerfsX4. This mutation is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Although this mutation has not been previously reported to our knowledge, it is predicted to be a pathogenic mutation. The variant is found in ACADM panel(s). -
Medium-chain acyl-coenzyme A dehydrogenase deficiency Pathogenic:1
Apr 23, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change creates a premature translational stop signal (p.Arg294Serfs*4) in the ACADM gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in ACADM are known to be pathogenic (PMID: 16121256, 20434380). This variant has not been reported in the literature in individuals with ACADM-related disease. ClinVar contains an entry for this variant (Variation ID: 203549). This variant is not present in population databases (ExAC no frequency). -