Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_001382391.1(CSPP1):c.2968+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000657 in 152,144 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Pathogenic (★★).
CSPP1 (HGNC:26193): (centrosome and spindle pole associated protein 1) This gene encodes a centrosome and spindle pole associated protein. The encoded protein plays a role in cell-cycle progression and spindle organization, regulates cytokinesis, interacts with Nephrocystin 8 and is required for cilia formation. Mutations in this gene result in primary cilia abnormalities and classical Joubert syndrome. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Apr 2014]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-67172556-G-A is Pathogenic according to our data. Variant chr8-67172556-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 100670.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-67172556-G-A is described in Lovd as [Likely_pathogenic]. Variant chr8-67172556-G-A is described in Lovd as [Pathogenic].
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 100670). This sequence change affects a donor splice site in intron 23 of the CSPP1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in CSPP1 are known to be pathogenic (PMID: 24360807, 24360808). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with Joubert syndrome (PMID: 24360808). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. -
Jan 02, 2014
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only
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Feb 23, 2015
UW Hindbrain Malformation Research Program, University of Washington
Significance: Pathogenic
Review Status: criteria provided, single submitter