Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PM2
The NM_002397.5(MEF2C):c.614_626delCGTCTGGTGCAGGinsGTCTCCAC(p.Thr205SerfsTer25) variant causes a frameshift, missense 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T205T) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
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]
Neurodevelopmental disorder with hypotonia, stereotypic hand movements, and impaired languageUncertain:1
Aug 20, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing
This sequence change creates a premature translational stop signal (p.Thr205Serfs*28) in the MEF2C gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). 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. This variant has not been reported in the literature in individuals with MEF2C-related disease. However, it has been observed in several individuals who were not affected with MEF2C-related disease (Invitae). -