rs1191508807

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_014946.4(SPAST):​c.1432G>A​(p.Asp478Asn) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,580 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D478V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SPAST
NM_014946.4 missense

Scores

3
12
4

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.03

Publications

0 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: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 uncertain in NM_014946.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 148 curated pathogenic missense variants (we use a threshold of 10). The gene has 21 curated benign missense variants. Gene score misZ: 1.2438 (below the threshold of 3.09). Trascript score misZ: 0.22274 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary spastic paraplegia 4, SPAST-related motor disorder, Charlevoix-Saguenay spastic ataxia, neurodevelopmental disorder.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPASTNM_014946.4 linkc.1432G>A p.Asp478Asn missense_variant Exon 12 of 17 ENST00000315285.9 NP_055761.2 Q9UBP0-1E5KRP5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPASTENST00000315285.9 linkc.1432G>A p.Asp478Asn missense_variant Exon 12 of 17 1 NM_014946.4 ENSP00000320885.3 Q9UBP0-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251224
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461580
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727114
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39658
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111786
Other (OTH)
AF:
0.00
AC:
0
AN:
60384
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 4 Uncertain:1
Oct 14, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SPAST-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. This sequence change replaces aspartic acid with asparagine at codon 478 of the SPAST protein (p.Asp478Asn). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and asparagine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.41
BayesDel_addAF
Benign
0.011
T
BayesDel_noAF
Benign
-0.22
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.86
D;D;.;.;.;.;.;.
Eigen
Uncertain
0.61
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
.;D;D;.;D;D;D;D
M_CAP
Uncertain
0.12
D
MetaRNN
Uncertain
0.67
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.55
D
MutationAssessor
Benign
1.5
L;L;.;.;.;.;.;.
PhyloP100
7.0
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-3.6
D;.;D;.;.;.;.;.
REVEL
Uncertain
0.55
Sift
Uncertain
0.0010
D;.;D;.;.;.;.;.
Sift4G
Uncertain
0.0030
D;D;D;.;.;.;.;.
Polyphen
0.98
D;D;.;.;.;.;.;.
Vest4
0.51
MutPred
0.55
Loss of catalytic residue at D478 (P = 0.1199);Loss of catalytic residue at D478 (P = 0.1199);.;.;.;.;.;.;
MVP
0.93
MPC
2.1
ClinPred
0.97
D
GERP RS
5.4
Varity_R
0.79
gMVP
0.86
Mutation Taster
=27/73
disease causing

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: rs1191508807; hg19: chr2-32362196; API