rs371753104

Variant summary

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

The NM_016630.7(SPG21):c.862A>G(p.Met288Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000948 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

SPG21
NM_016630.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 5.79

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 links:

Genome browser will be placed here

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=0.08793765).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
SPG21	NM_016630.7 linkuse as main transcript	c.862A>G	p.Met288Val	missense_variant	9/9	ENST00000204566.7
SPG21	NM_001127889.5 linkuse as main transcript	c.862A>G	p.Met288Val	missense_variant	9/9
SPG21	NM_001127890.5 linkuse as main transcript	c.781A>G	p.Met261Val	missense_variant	8/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SPG21	ENST00000204566.7 linkuse as main transcript	c.862A>G	p.Met288Val	missense_variant	9/9	1	NM_016630.7	P1	Q9NZD8-1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000835

AC:

AN:

251446

Hom.:

AF XY:

0.0000809

AC XY:

AN XY:

135890

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000132

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000999

AC:

146

AN:

1461856

Hom.:

Cov.:

AF XY:

0.0000963

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000121

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000965

Hom.:

Bravo

AF:

0.0000718

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000741

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 22, 2022

The c.862A>G (p.M288V) alteration is located in exon 9 (coding exon 8) of the SPG21 gene. This alteration results from a A to G substitution at nucleotide position 862, causing the methionine (M) at amino acid position 288 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary spastic paraplegia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Dec 12, 2016

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 11, 2019

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Mast syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 29, 2022

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 288 of the SPG21 protein (p.Met288Val). This variant is present in population databases (rs371753104, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SPG21-related conditions. ClinVar contains an entry for this variant (Variation ID: 573515). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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

Benign

0.071

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.33

Cadd

Benign

Dann

Benign

0.93

DEOGEN2

Benign

0.14

T;.;T;.

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.071

FATHMM_MKL

Pathogenic

0.98

M_CAP

Benign

0.0033

MetaRNN

Benign

0.088

T;T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.81

L;.;L;.

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Benign

0.47

PROVEAN

Benign

-0.46

N;N;N;N

REVEL

Benign

0.072

Sift

Benign

0.33

T;T;T;T

Sift4G

Benign

0.83

T;T;T;T

Polyphen

0.0

B;.;B;B

Vest4

0.25

MVP

0.22

MPC

0.33

ClinPred

0.025

GERP RS

4.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.10

gMVP

0.71

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over