rs754903980

chr16-89531983-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_003119.4(SPG7):c.1067C>T(p.Thr356Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,552 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T356T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: SPG7 NM_003119.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.63

Genes affected

SPG7 (HGNC:11237): (SPG7 matrix AAA peptidase subunit, paraplegin) This gene encodes a mitochondrial metalloprotease protein that is a member of the AAA family. Members of this protein family share an ATPase domain and have roles in diverse cellular processes including membrane trafficking, intracellular motility, organelle biogenesis, protein folding, and proteolysis. Mutations in this gene cause autosomal recessive spastic paraplegia 7. Two transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Mar 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_003119.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SPG7	NM_003119.4	c.1067C>T	p.Thr356Met	missense_variant	8/17	ENST00000645818.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SPG7	ENST00000645818.2	c.1067C>T	p.Thr356Met	missense_variant	8/17		NM_003119.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250520 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135624

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461552 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727094

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 11, 2022

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. 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) performed at Invitae indicates that this missense variant is expected to disrupt SPG7 protein function. ClinVar contains an entry for this variant (Variation ID: 533736). This missense change has been observed in individual(s) with ataxia and spasticity (PMID: 24727571). This variant is present in population databases (rs754903980, gnomAD 0.003%). This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 356 of the SPG7 protein (p.Thr356Met). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	29
Dann	Pathogenic	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.82	D
Polyphen		1.0	.;.;D;.;.;.;.;.;D
Vest4		0.99
MutPred		0.83		.;.;Loss of methylation at K355 (P = 0.0307);Loss of methylation at K355 (P = 0.0307);Loss of methylation at K355 (P = 0.0307);Loss of methylation at K355 (P = 0.0307);Loss of methylation at K355 (P = 0.0307);.;Loss of methylation at K355 (P = 0.0307);
MVP		0.99
MPC		0.81
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		3.1
Varity_R		0.92
gMVP		0.93

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

Other links and lift over

dbSNP: rs754903980; hg19: chr16-89598391; COSMIC: COSV51948722; COSMIC: COSV51948722;