chr15-64963702-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_016630.7(SPG21):​c.845C>T​(p.Ala282Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,984 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. A282T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

SPG21
NM_016630.7 missense

Scores

1
4
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.41
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.2547099).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
SPG21NM_016630.7 linkuse as main transcriptc.845C>T p.Ala282Val missense_variant 9/9 ENST00000204566.7
SPG21NM_001127889.5 linkuse as main transcriptc.845C>T p.Ala282Val missense_variant 9/9
SPG21NM_001127890.5 linkuse as main transcriptc.764C>T p.Ala255Val missense_variant 8/8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
SPG21ENST00000204566.7 linkuse as main transcriptc.845C>T p.Ala282Val missense_variant 9/91 NM_016630.7 P1Q9NZD8-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1461792
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
727212
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000899
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74348
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000860
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsJan 30, 2024The c.845C>T (p.A282V) alteration is located in exon 9 (coding exon 8) of the SPG21 gene. This alteration results from a C to T substitution at nucleotide position 845, causing the alanine (A) at amino acid position 282 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.52
BayesDel_addAF
Benign
0.0040
T
BayesDel_noAF
Benign
-0.23
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.18
T;.;T;.
Eigen
Benign
-0.11
Eigen_PC
Benign
-0.050
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
.;D;D;D
M_CAP
Benign
0.0087
T
MetaRNN
Benign
0.25
T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.69
N;.;N;.
MutationTaster
Benign
1.0
D;D;D;D
PrimateAI
Uncertain
0.73
T
PROVEAN
Benign
-1.0
N;N;N;N
REVEL
Benign
0.25
Sift
Benign
0.23
T;T;T;T
Sift4G
Benign
0.47
T;D;T;T
Polyphen
0.97
D;.;D;P
Vest4
0.49
MutPred
0.65
Gain of sheet (P = 0.0827);.;Gain of sheet (P = 0.0827);.;
MVP
0.29
MPC
0.42
ClinPred
0.63
D
GERP RS
3.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.069
gMVP
0.61

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs183121219; hg19: chr15-65256043; API