Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_ModeratePM2
The NM_001377540.1(SLMAP):c.347-1G>T variant causes a splice acceptor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).
SLMAP (HGNC:16643): (sarcolemma associated protein) This gene encodes a component of a conserved striatin-interacting phosphatase and kinase complex. Striatin family complexes participate in a variety of cellular processes including signaling, cell cycle control, cell migration, Golgi assembly, and apoptosis. The protein encoded by this gene is a coiled-coil, tail-anchored membrane protein with a single C-terminal transmembrane domain that is posttranslationally inserted into membranes. Mutations in this gene are associated with Brugada syndrome, a cardiac channelopathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2015]
Verdict is Uncertain_significance. Variant got 4 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.028865164 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.1, offset of 45, new splice context is: aataaaactttttctaccAGatg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in SLMAP cause disease. Therefore, this variant has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a SLMAP-related disease. This sequence change affects an acceptor splice site in intron 2 of the SLMAP gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -