chr16-89544770-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1PM2PP3PP5_Very_Strong

The NM_003119.4(SPG7):​c.1447C>T​(p.Gln483Ter) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,613,994 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SPG7
NM_003119.4 stop_gained, splice_region

Scores

4
2
1
Splicing: ADA: 0.9992
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 7.79
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 19 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;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 16-89544770-C-T is Pathogenic according to our data. Variant chr16-89544770-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 390378.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.1447C>T p.Gln483Ter stop_gained, splice_region_variant 10/17 ENST00000645818.2 NP_003110.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
SPG7ENST00000645818.2 linkuse as main transcriptc.1447C>T p.Gln483Ter stop_gained, splice_region_variant 10/17 NM_003119.4 ENSP00000495795 P2Q9UQ90-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152238
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000169
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000119
AC:
3
AN:
251214
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135816
show subpopulations
Gnomad AFR exome
AF:
0.000123
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:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461638
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727122
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:
0.00000270
Gnomad4 OTH exome
AF:
0.0000497
GnomAD4 genome
AF:
0.0000459
AC:
7
AN:
152356
Hom.:
0
Cov.:
32
AF XY:
0.0000537
AC XY:
4
AN XY:
74506
show subpopulations
Gnomad4 AFR
AF:
0.000168
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:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000529
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 7 Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 19, 2021This variant is present in population databases (rs562890289, gnomAD 0.02%). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 390378). This premature translational stop signal has been observed in individual(s) with clinical features of SPG7-related conditions (PMID: 28832565, 33841295). This sequence change creates a premature translational stop signal (p.Gln483*) 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). -
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 13, 2023Variant summary: SPG7 c.1447C>T (p.Gln483X) results in a premature termination codon, predicted to cause an absence of the protein due to nonsense mediated decay, a commonly known mechanism for disease. The variant allele was found at a frequency of 1.2e-05 in 251214 control chromosomes (gnomAD). c.1447C>T has been reported in the literature in individuals affected with Hereditary Spastic Paraplegia 7 (e.g. Morais_2017). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 28832565). Three submitters have provided clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as pathogenic (n=2)/likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Hereditary spastic paraplegia Pathogenic:1
Pathogenic, criteria provided, single submitterresearchUnit for Genetic & Epidemiological Research on Neurological Disorders, Instituto de Investigação e Inovação em SaúdeMar 07, 2017- -
not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingGeneDxNov 01, 2016The Q483X variant in the SPG7 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The Q483X variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret Q483X as a likely pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.66
CADD
Pathogenic
62
DANN
Uncertain
1.0
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.54
FATHMM_MKL
Pathogenic
0.99
D
MutationTaster
Benign
1.0
A
GERP RS
4.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.86
SpliceAI score (max)
0.95
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.95
Position offset: -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: rs562890289; hg19: chr16-89611178; API