rs570685843

Variant names:

• chr2-32136968-TGTAA-T
• rs570685843
• NM_014946.4:c.1413+3_1413+6delAAGT

Variant summary

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

The ENST00000315285.9(SPAST):​c.1413+1_1413+4delGTAA variant causes a splice donor, splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SPAST ENST00000315285.9 splice_donor, splice_region, intron
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.36

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, Cryptic splice site detected, with MaxEntScore 4.8, offset of -2, new splice context is: atgGTgtgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-32136968-TGTAA-T is Pathogenic according to our data. Variant chr2-32136968-TGTAA-T is described in ClinVar as [Pathogenic]. Clinvar id is 536445.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.1413+3_1413+6delAAGT		splice_region_variant, intron_variant	Intron 11 of 16	ENST00000315285.9	NP_055761.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPAST	ENST00000315285.9	c.1413+1_1413+4delGTAA		splice_donor_variant, splice_region_variant, intron_variant	Intron 11 of 16	1	NM_014946.4	ENSP00000320885.3

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary spastic paraplegia 4 Pathogenic:4

Jan 01, 2016

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PVS1,PM2,PP3. -

-

Paris Brain Institute, Inserm - ICM

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 06, 2021

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0103 - Dominant Negative and loss-of-function are known mechanisms of disease for this gene and are associated with spastic paraplegia 4 (MIM#182601). Multiple loss of function variants have been reported, while a dominant negative mechanism has been stipulated for a small number of missense variants (ClinVar; PMID: 30006150). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0112 - The condition associated with this gene has incomplete penetrance, but this is age-dependant and only a small proportion of individuals remain asymptomatic (PMID: 30476002). (I) 0115 - Variants in this gene are known to have variable expressivity, with variable age of onset and disease severity (PMID: 30476002). (I) 0212 - Non-canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0505 - Abnormal splicing is predicted by in silico tools and affected nucleotide is highly conserved. (SP) 0702 - Other splice variants comparable to the one identified in this case have strong previous evidence for pathogenicity. Many different variants affecting the deleted nucleotides of this variant (c.1413+5G>C, c.1413+5G>A, c.1413+4A>G, c.1413+3A>C and c.1413+6T>C) have been reported as pathogenic and likely pathogenic in patients with hereditary spastic paraplegia (ClinVar, PMID: 30375765). (SP) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported as pathogenic and likely pathogenic, in multiple patients with hereditary spastic paraplegia (ClinVar, PMID: 10699187, PMID: 26671083, PMID: 15841487, PMID: 23252998). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Apr 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 11 of the SPAST gene. It does not directly change the encoded amino acid sequence of the SPAST protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with clinical features of hereditary spastic paraplegia (PMID: 10699187, 26671083, 34816117; Invitae). This variant is also known as c.1538+3del4. ClinVar contains an entry for this variant (Variation ID: 536445). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.43		Position offset: -2
DS_DL_spliceai		0.99		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs570685843; hg19: chr2-32362037;