rs145776296

chr16-89524213-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_003119.4(SPG7):c.584A>G(p.Tyr195Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000114 in 1,612,808 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000086 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00012 (0 hom.)
• Consequence: SPG7 NM_003119.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 3.42

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.767

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SPG7	NM_003119.4	c.584A>G	p.Tyr195Cys	missense_variant	4/17	ENST00000645818.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SPG7	ENST00000645818.2	c.584A>G	p.Tyr195Cys	missense_variant	4/17		NM_003119.4	P2

Frequencies

GnomAD3 genomes AF: 0.0000856 AC: 13 AN: 151840 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000485

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: 0.000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000478 AC: 12 AN: 251076 Hom.: 0 AF XY: 0.0000368 AC XY: 5 AN XY: 135756

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000969

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000117 AC: 171 AN: 1460968 Hom.: 0 Cov.: 31 AF XY: 0.000114 AC XY: 83 AN XY: 726698

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: 0.000150

Gnomad4 OTH exome AF: 0.0000663

GnomAD4 genome AF: 0.0000856 AC: 13 AN: 151840 Hom.: 0 Cov.: 32 AF XY: 0.0000539 AC XY: 4 AN XY: 74168

Gnomad4 AFR AF: 0.0000485

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: 0.000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000112 Hom.: 0

Bravo AF: 0.0000718

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000519 AC: 2

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.0000412 AC: 5

EpiCase AF: 0.000109

EpiControl AF: 0.000178

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 14, 2015	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 14, 2017	p.Tyr195Cys (TAC>TGC), c.584 A>G in exon 4 of the SPG7 gene (NM_003119.2). The Y195C missense substitution in the SPG7 gene has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. The amino acid substitution is semi-conservative in that both Tyrosine and Cysteine are uncharged, polar amino acids; however, the introduction of a Cysteine residue may introduce disulfide bonds in the SPG7 protein and impact the secondary structure of this protein. This change occurs at a position in the SPG7 protein that is not highly conserved. In-silico analyses are not consistent in their predictions as to whether or not Y195C is likely to be damaging to the SPG7 protein. Therefore, based on the currently available information it is unclear whether Y195C is a disease-causing mutation or a rare benign variant. The variant is found in OAPEO-MITOP panel(s). -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 21, 2023

Variant summary: SPG7 c.584A>G (p.Tyr195Cys) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.8e-05 in 251076 control chromosomes (gnomAD). To our knowledge, no occurrence of c.584A>G in individuals affected with Hereditary Spastic Paraplegia 7 and no experimental evidence demonstrating its impact on protein function have been reported. Three submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary spastic paraplegia 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 19, 2023

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 not expected to disrupt SPG7 protein function. ClinVar contains an entry for this variant (Variation ID: 215205). This variant has not been reported in the literature in individuals affected with SPG7-related conditions. This variant is present in population databases (rs145776296, gnomAD 0.01%). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 195 of the SPG7 protein (p.Tyr195Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.43
BayesDel_addAF	Uncertain	0.042	T
BayesDel_noAF	Uncertain	0.030
Cadd	Uncertain	24
Dann	Uncertain	1.0
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.77	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.081	T
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.75	T
Polyphen		1.0, 1.0	.;.;D;.;.;.;.;.;.;.;D
Vest4		0.77, 0.78
MVP		0.93
MPC		0.84
ClinPred		0.85	D
GERP RS		3.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.42
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs145776296; hg19: chr16-89590621;