Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP2PP3_Moderate
The NM_002397.5(MEF2C):c.1391G>C(p.Arg464Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R464R) has been classified as Likely benign.
MEF2C (HGNC:6996): (myocyte enhancer factor 2C) This locus encodes a member of the MADS box transcription enhancer factor 2 (MEF2) family of proteins, which play a role in myogenesis. The encoded protein, MEF2 polypeptide C, has both trans-activating and DNA binding activities. This protein may play a role in maintaining the differentiated state of muscle cells. Mutations and deletions at this locus have been associated with severe cognitive disability, stereotypic movements, epilepsy, and cerebral malformation. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jul 2010]
Verdict is Uncertain_significance. Variant got 5 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MEF2C. . Gene score misZ 3.9523 (greater than the threshold 3.09). Trascript score misZ 4.8218 (greater than threshold 3.09). GenCC has associacion of gene with intellectual disability, autosomal dominant 20, complex neurodevelopmental disorder.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.841
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
May 15, 2023
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -