rs1553319298

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_014946.4(SPAST):​c.1577_1580delGAAG​(p.Gly526ValfsTer3) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,154 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

SPAST
NM_014946.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 8.78

Publications

1 publications found
Variant links:
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]
SPAST Gene-Disease associations (from GenCC):
  • hereditary spastic paraplegia 4
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Illumina, Genomics England PanelApp, Ambry Genetics
  • Charlevoix-Saguenay spastic ataxia
    Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
  • neurodevelopmental disorder
    Inheritance: AD Classification: STRONG Submitted by: G2P
  • SPAST-related motor disorder
    Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 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 2-32143372-CAAGG-C is Pathogenic according to our data. Variant chr2-32143372-CAAGG-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 536440.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
SPASTNM_014946.4 linkc.1577_1580delGAAG p.Gly526ValfsTer3 frameshift_variant Exon 14 of 17 ENST00000315285.9 NP_055761.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPASTENST00000315285.9 linkc.1577_1580delGAAG p.Gly526ValfsTer3 frameshift_variant Exon 14 of 17 1 NM_014946.4 ENSP00000320885.3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.86e-7
AC:
1
AN:
1457154
Hom.:
0
AF XY:
0.00000138
AC XY:
1
AN XY:
725120
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33404
American (AMR)
AF:
0.00
AC:
0
AN:
44622
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26030
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39594
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85926
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53354
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5704
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1108302
Other (OTH)
AF:
0.00
AC:
0
AN:
60218
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:3
Jul 19, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PM2, PVS1 -

Jul 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

SPAST: PVS1, PM2, PS4:Supporting -

Jan 16, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 12552568) -

Hereditary spastic paraplegia 4 Pathogenic:1
Aug 17, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is also known as 1702_1705delGAAG. For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 536440). This premature translational stop signal has been observed in individuals with spastic paraplegia (PMID: 12552568; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly526Valfs*3) in the SPAST gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SPAST are known to be pathogenic (PMID: 20932283). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
8.8
Mutation Taster
=0/200
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1553319298; hg19: chr2-32368441; API