Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_ModeratePP5_Moderate
The NM_001048166.1(STIL):c.453+5G>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).
STIL (HGNC:10879): (STIL centriolar assembly protein) This gene encodes a cytoplasmic protein implicated in regulation of the mitotic spindle checkpoint, a regulatory pathway that monitors chromosome segregation during cell division to ensure the proper distribution of chromosomes to daughter cells. The protein is phosphorylated in mitosis and in response to activation of the spindle checkpoint, and disappears when cells transition to G1 phase. It interacts with a mitotic regulator, and its expression is required to efficiently activate the spindle checkpoint. It is proposed to regulate Cdc2 kinase activity during spindle checkpoint arrest. Chromosomal deletions that fuse this gene and the adjacent locus commonly occur in T cell leukemias, and are thought to arise through illegitimate V-(D)-J recombination events. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 1-47301556-C-A is Pathogenic according to our data. Variant chr1-47301556-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 451761.Status of the report is criteria_provided_single_submitter, 1 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.453+5G>T variant in the STIL gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant reduces the quality of the splice donor site in intron 5, and is predicted to cause abnormal gene splicing. The c.453+5G>T variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). We interpret c.453+5G>T as a likely pathogenic variant. -