chr8-67175377-C-T

Position:

• chr8-67175377-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001382391.1(CSPP1):​c.3050C>T​(p.Ala1017Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CSPP1 NM_001382391.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.37

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]

CSPP1 (HGNC:):

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.748

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CSPP1	NM_001382391.1	c.3050C>T	p.Ala1017Val	missense_variant	26/31	ENST00000678616.1	NP_001369320.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CSPP1	ENST00000678616.1	c.3050C>T	p.Ala1017Val	missense_variant	26/31		NM_001382391.1	ENSP00000504733.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Joubert syndrome 21 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 15, 2019

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with CSPP1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with valine at codon 1012 of the CSPP1 protein (p.Ala1012Val). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
CADD	Pathogenic	26
DANN	Pathogenic	1.0
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.81	T;T
M_CAP	Benign	0.057	D
MetaRNN	Pathogenic	0.75	D;D
MetaSVM	Benign	-0.32	T
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-2.2	N;N
REVEL	Benign	0.24
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.023	D;D
Polyphen		1.0	D;D
Vest4		0.66
MVP		0.77
MPC		0.58
ClinPred		0.99	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.17

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1831355993; hg19: chr8-68087612;