15-64963703-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_016630.7(SPG21):​c.844G>A​(p.Ala282Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000155 in 1,613,998 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. 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. A282V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

SPG21
NM_016630.7 missense

Scores

1
3
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.47

Publications

1 publications found
Variant links:
Genes affected
SPG21 (HGNC:20373): (SPG21 abhydrolase domain containing, maspardin) The protein encoded by this gene binds to the hydrophobic C-terminal amino acids of CD4 which are involved in repression of T cell activation. The interaction with CD4 is mediated by the noncatalytic alpha/beta hydrolase fold domain of this protein. It is thus proposed that this gene product modulates the stimulatory activity of CD4. Mutations in this gene are associated with autosomal recessive spastic paraplegia 21 (SPG21), also known as mast syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]
SPG21 Gene-Disease associations (from GenCC):
  • mast syndrome
    Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: PanelApp Australia, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.1763157).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016630.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPG21
NM_016630.7
MANE Select
c.844G>Ap.Ala282Thr
missense
Exon 9 of 9NP_057714.1Q9NZD8-1
SPG21
NM_001127889.5
c.844G>Ap.Ala282Thr
missense
Exon 9 of 9NP_001121361.1Q9NZD8-1
SPG21
NM_001127890.5
c.763G>Ap.Ala255Thr
missense
Exon 8 of 8NP_001121362.1Q9NZD8-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPG21
ENST00000204566.7
TSL:1 MANE Select
c.844G>Ap.Ala282Thr
missense
Exon 9 of 9ENSP00000204566.2Q9NZD8-1
SPG21
ENST00000433215.6
TSL:1
c.844G>Ap.Ala282Thr
missense
Exon 9 of 9ENSP00000404111.2Q9NZD8-1
SPG21
ENST00000854124.1
c.844G>Ap.Ala282Thr
missense
Exon 9 of 9ENSP00000524183.1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251408
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1461810
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
727216
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000176
AC:
7
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5742
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1111990
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.464
Heterozygous variant carriers
0
2
3
5
6
8
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
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74346
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68048
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.000108
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000165
AC:
2

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:criteria provided, single submitter
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
-
Mast syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.21
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.23
CADD
Benign
21
DANN
Uncertain
0.99
DEOGEN2
Benign
0.15
T
Eigen
Benign
-0.32
Eigen_PC
Benign
-0.20
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D
M_CAP
Benign
0.0062
T
MetaRNN
Benign
0.18
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.69
N
PhyloP100
4.5
PrimateAI
Uncertain
0.70
T
PROVEAN
Benign
-0.35
N
REVEL
Benign
0.26
Sift
Benign
0.056
T
Sift4G
Benign
0.34
T
Polyphen
0.28
B
Vest4
0.45
MutPred
0.60
Gain of sheet (P = 0.0827)
MVP
0.23
MPC
0.36
ClinPred
0.18
T
GERP RS
3.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.063
gMVP
0.57
Mutation Taster
=64/36
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.080
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: rs749945579; hg19: chr15-65256044; API