8-67175307-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001382391.1(CSPP1):c.2980C>T(p.Arg994Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000549 in 1,456,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: CSPP1 NM_001382391.1 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.98

Genes affected

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]

ARFGEF1 (HGNC:15772): (ADP ribosylation factor guanine nucleotide exchange factor 1) ADP-ribosylation factors (ARFs) play an important role in intracellular vesicular trafficking. The protein encoded by this gene is involved in the activation of ARFs by accelerating replacement of bound GDP with GTP. It contains a Sec7 domain, which may be responsible for guanine-nucleotide exchange activity and also brefeldin A inhibition. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-67175307-C-T is Pathogenic according to our data. Variant chr8-67175307-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1069030.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CSPP1	NM_001382391.1	c.2980C>T	p.Arg994Ter	stop_gained	26/31	ENST00000678616.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CSPP1	ENST00000678616.1	c.2980C>T	p.Arg994Ter	stop_gained	26/31		NM_001382391.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000810 AC: 2 AN: 246776 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 133898

Gnomad AFR exome AF: 0.0000648

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000333

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000549 AC: 8 AN: 1456880 Hom.: 0 Cov.: 29 AF XY: 0.00000276 AC XY: 2 AN XY: 724780

Gnomad4 AFR exome AF: 0.0000301

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000451

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000413 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000828 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Joubert syndrome 21 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Sep 27, 2022

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 1069030). This variant has not been reported in the literature in individuals affected with CSPP1-related conditions. This variant is present in population databases (rs760275528, gnomAD 0.007%). This sequence change creates a premature translational stop signal (p.Arg989*) in the CSPP1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CSPP1 are known to be pathogenic (PMID: 24360807, 24360808). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	38
Dann	Uncertain	1.0
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.97	D
MutationTaster	Benign	1.0	D;A;A;A
Vest4		0.45
GERP RS		2.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs760275528; hg19: chr8-68087542;