16-89529488-CTG-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_003119.4(SPG7):​c.773_774del​(p.Val258GlyfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,612,884 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SPG7
NM_003119.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 0.284
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-89529488-CTG-C is Pathogenic according to our data. Variant chr16-89529488-CTG-C is described in ClinVar as [Pathogenic]. Clinvar id is 504920.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
SPG7NM_003119.4 linkuse as main transcriptc.773_774del p.Val258GlyfsTer30 frameshift_variant 6/17 ENST00000645818.2 NP_003110.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
SPG7ENST00000645818.2 linkuse as main transcriptc.773_774del p.Val258GlyfsTer30 frameshift_variant 6/17 NM_003119.4 ENSP00000495795 P2Q9UQ90-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152220
Hom.:
0
Cov.:
33
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:
0.000478
GnomAD3 exomes
AF:
0.00000803
AC:
2
AN:
249210
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
134930
show subpopulations
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:
0.0000329
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000165
GnomAD4 exome
AF:
0.00000411
AC:
6
AN:
1460664
Hom.:
0
AF XY:
0.00000275
AC XY:
2
AN XY:
726648
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:
0.00000450
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152220
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74360
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:
0.000478
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 7 Pathogenic:5
Pathogenic, no assertion criteria providedliterature onlyOMIMJun 12, 1998- -
Pathogenic, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 15, 2024This sequence change creates a premature translational stop signal (p.Val258Glyfs*30) in the SPG7 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SPG7 are known to be pathogenic (PMID: 21623769, 22964162). This variant is present in population databases (rs768136171, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with autosomal recessive hereditary spastic paraplegia (PMID: 9635427). This variant is also known as 784del2. ClinVar contains an entry for this variant (Variation ID: 504920). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterresearchPROSPAX: an integrated multimodal progression chart in spastic ataxias, Center for Neurology; Hertie-Institute for Clinical Brain ResearchJan 01, 2022- -
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMar 24, 2022- -
SPG7-related disorder Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesNov 21, 2022The SPG7 c.773_774delTG variant is predicted to result in a frameshift and premature protein termination (p.Val258Glyfs*30). This variant was reported in the homozygous and compound heterozygous states in patients with hereditary spastic paraplegia (Casari et al. 1998. PubMed ID: 9635427; da Graça et al. 2021. PubMed ID: 33956305; Table S2 in Mancini et al. 2019. PubMed ID: 30098094; Primiano et al. 2020. PubMed ID: 32317346). This variant was also found in a patient with dominant optic atrophy (Charif et al. 2020. PubMed ID: 32548275). This variant is reported in 0.0033% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-89595896-CTG-C). Frameshift variants in SPG7 are expected to be pathogenic. This variant is interpreted as pathogenic. -
Hereditary spastic paraplegia Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineMar 28, 2016The p.Val258GlyfsX30 variant in SPG7 has been reported in one homozygous individ ual with spastic papaplegia (Casari 1998) and was identified in 2/105,040 of chr omosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.o rg). This variant causes a frameshift, which is predicted to alter the protein?s amino acid sequence beginning at position 258 and lead to a premature terminati on codon 30 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Variants causing loss of function in the SPG7 ge ne are associated with spastic paraplegia. In summary, this variant meets our cr iteria to be classified as pathogenic for spastic paraplegia in an autosomal rec essive manner based upon its predicted functional impact and homozygous case obs ervation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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.

Other links and lift over

dbSNP: rs768136171; hg19: chr16-89595896; API