rs1553314978

Variant names:

• chr2-32114826-G-A
• rs1553314978
• NM_014946.4:c.870+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr2-32114826-G-A
• chr2-32114826-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_014946.4(SPAST):​c.870+1G>A variant causes a splice donor, intron change. 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 Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SPAST NM_014946.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.00

Genes affected

SPAST (HGNC:11233): (spastin) This gene encodes a member of the AAA (ATPases associated with a variety of cellular activities) protein family. Members of this protein family share an ATPase domain and have roles in diverse cellular processes including membrane trafficking, intracellular motility, organelle biogenesis, protein folding, and proteolysis. The use of alternative translational initiation sites in this gene results in a single transcript variant that can produce isoforms that differ in the length of their N-terminus and which thereby differ in the efficiency of their export from the nucleus to the cytoplasm. In addition, alternative splicing results in multiple transcript variants that encode isoforms that differ in other protein regions as well. One isoform of this gene has been shown to be a microtubule-severing enzyme that regulates microtubule abundance, mobility, and plus-end distribution. Mutations in this gene cause the most frequent form of autosomal dominant spastic paraplegia 4. [provided by RefSeq, May 2018]

ACMG classification

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 2-32114826-G-A is Pathogenic according to our data. Variant chr2-32114826-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 523508.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPAST	NM_014946.4	c.870+1G>A		splice_donor_variant, intron_variant	Intron 5 of 16	ENST00000315285.9	NP_055761.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPAST	ENST00000315285.9	c.870+1G>A		splice_donor_variant, intron_variant	Intron 5 of 16	1	NM_014946.4	ENSP00000320885.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Spastic paraplegia Pathogenic:1

Jan 01, 2017

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary spastic paraplegia 4 Pathogenic:1

Feb 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 5 of the SPAST 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 SPAST are known to be pathogenic (PMID: 20932283). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with hereditary spastic paraplegia (PMID: 25341883). ClinVar contains an entry for this variant (Variation ID: 523508). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the c.870+1delG nucleotide in the SPAST gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 23833562). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	27
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.99	D
GERP RS		4.6

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.94		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.94		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553314978; hg19: chr2-32339895;