Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong
The NM_000016.6(ACADM):c.1150G>T(p.Glu384*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,613,808 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 Likely pathogenic (★★).
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 14 ACMG points.
PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 17 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-75761326-G-T is Pathogenic according to our data. Variant chr1-75761326-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 371122.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Medium-chain acyl-coenzyme A dehydrogenase deficiency Pathogenic:2
Jul 08, 2016
Counsyl
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Nov 02, 2023
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.Glu384*) in the ACADM gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 38 amino acid(s) of the ACADM protein. This variant is present in population databases (rs748110745, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with MCAD deficiency (PMID: 8198141). ClinVar contains an entry for this variant (Variation ID: 371122). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects ACADM function (PMID: 8198141). For these reasons, this variant has been classified as Pathogenic. -