chr15-64963676-C-T

Variant summary

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

The NM_016630.7(SPG21):​c.871G>A​(p.Ala291Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A291A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

SPG21
NM_016630.7 missense

Scores

1
3
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.59
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=0.14509273).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
SPG21NM_016630.7 linkuse as main transcriptc.871G>A p.Ala291Thr missense_variant 9/9 ENST00000204566.7
SPG21NM_001127889.5 linkuse as main transcriptc.871G>A p.Ala291Thr missense_variant 9/9
SPG21NM_001127890.5 linkuse as main transcriptc.790G>A p.Ala264Thr missense_variant 8/8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
SPG21ENST00000204566.7 linkuse as main transcriptc.871G>A p.Ala291Thr missense_variant 9/91 NM_016630.7 P1Q9NZD8-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152216
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
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461832
Hom.:
0
Cov.:
31
AF XY:
0.0000151
AC XY:
11
AN XY:
727228
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:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000252
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152216
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74370
show subpopulations
Gnomad4 AFR
AF:
0.0000241
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
Bravo
AF:
0.0000113
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

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 GeneticsSep 28, 2022The c.871G>A (p.A291T) alteration is located in exon 9 (coding exon 8) of the SPG21 gene. This alteration results from a G to A substitution at nucleotide position 871, causing the alanine (A) at amino acid position 291 to be replaced by a threonine (T). 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
Benign
0.068
BayesDel_addAF
Benign
-0.046
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Benign
0.13
T;.;T;.
Eigen
Benign
-0.045
Eigen_PC
Benign
0.18
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.93
.;D;D;D
M_CAP
Benign
0.0036
T
MetaRNN
Benign
0.15
T;T;T;T
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
0.55
N;.;N;.
MutationTaster
Benign
1.0
D;D;D;D
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-0.17
N;N;N;N
REVEL
Benign
0.27
Sift
Benign
0.079
T;T;T;T
Sift4G
Benign
0.36
T;T;T;T
Polyphen
0.047
B;.;B;B
Vest4
0.20
MutPred
0.22
Gain of glycosylation at A291 (P = 0.018);.;Gain of glycosylation at A291 (P = 0.018);.;
MVP
0.28
MPC
0.33
ClinPred
0.50
D
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.080
gMVP
0.72

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs1236363525; hg19: chr15-65256017; API