rs780452995

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_015087.5(SPART):​c.720T>G​(p.Ser240Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S240I) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SPART
NM_015087.5 missense

Scores

4
11
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.92

Publications

1 publications found
Variant links:
Genes affected
SPART (HGNC:18514): (spartin) This gene encodes a protein containing a MIT (Microtubule Interacting and Trafficking molecule) domain, and is implicated in regulating endosomal trafficking and mitochondria function. The protein localizes to mitochondria and partially co-localizes with microtubules. Stimulation with epidermal growth factor (EGF) results in protein translocation to the plasma membrane, and the protein functions in the degradation and intracellular trafficking of EGF receptor. Multiple alternatively spliced variants, encoding the same protein, have been identified. Mutations associated with this gene cause autosomal recessive spastic paraplegia 20 (Troyer syndrome). [provided by RefSeq, Nov 2008]
SPART Gene-Disease associations (from GenCC):
  • Troyer syndrome
    Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.807

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPARTNM_015087.5 linkc.720T>G p.Ser240Arg missense_variant Exon 2 of 9 ENST00000438666.7 NP_055902.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPARTENST00000438666.7 linkc.720T>G p.Ser240Arg missense_variant Exon 2 of 9 1 NM_015087.5 ENSP00000406061.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251362
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000868
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461856
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111986
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Apr 12, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.720T>G (p.S240R) alteration is located in exon 2 (coding exon 1) of the SPG20 gene. This alteration results from a T to G substitution at nucleotide position 720, causing the serine (S) at amino acid position 240 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Oct 13, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 240 of the SPART protein (p.Ser240Arg). This variant is present in population databases (no rsID available, gnomAD 0.009%). This variant has not been reported in the literature in individuals affected with SPART-related conditions. ClinVar contains an entry for this variant (Variation ID: 2195244). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SPART protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Uncertain
0.15
D
BayesDel_noAF
Pathogenic
0.18
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Benign
0.35
T;T;T;T;T
Eigen
Uncertain
0.26
Eigen_PC
Benign
0.20
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.95
.;.;D;.;.
M_CAP
Uncertain
0.15
D
MetaRNN
Pathogenic
0.81
D;D;D;D;D
MetaSVM
Uncertain
0.49
D
PhyloP100
2.9
PrimateAI
Uncertain
0.76
T
PROVEAN
Uncertain
-3.6
D;D;D;.;.
REVEL
Pathogenic
0.71
Sift
Uncertain
0.0010
D;D;D;.;.
Sift4G
Uncertain
0.0020
D;D;D;.;D
Polyphen
1.0
D;D;D;D;D
Vest4
0.81
MutPred
0.62
Gain of catalytic residue at A236 (P = 0);Gain of catalytic residue at A236 (P = 0);Gain of catalytic residue at A236 (P = 0);Gain of catalytic residue at A236 (P = 0);Gain of catalytic residue at A236 (P = 0);
MVP
0.95
MPC
0.45
ClinPred
0.93
D
GERP RS
1.8
Varity_R
0.69
gMVP
0.86
Mutation Taster
=60/40
polymorphism

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: rs780452995; hg19: chr13-36909248; API