16-89529568-TT-C

Position:

• chr16-89529568-TT-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_003119.4(SPG7):​c.850_851delTTinsC​(p.Phe284fs) variant causes a frameshift, missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F284S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SPG7 NM_003119.4 frameshift, missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.77

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]

SPG7 (HGNC:):

ACMG classification

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 16-89529568-TT-C is Pathogenic according to our data. Variant chr16-89529568-TT-C is described in ClinVar as [Pathogenic]. Clinvar id is 533735.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
SPG7	NM_003119.4	c.850_851delTTinsC	p.Phe284fs	frameshift_variant, missense_variant	6/17	ENST00000645818.2	NP_003110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPG7	ENST00000645818.2	c.850_851delTTinsC	p.Phe284fs	frameshift_variant, missense_variant	6/17		NM_003119.4	ENSP00000495795.2

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary spastic paraplegia 7 Pathogenic:4

Pathogenic, criteria provided, single submitter	research	PROSPAX: an integrated multimodal progression chart in spastic ataxias, Center for Neurology; Hertie-Institute for Clinical Brain Research	Jan 01, 2022	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 14, 2006	- -
Pathogenic, criteria provided, single submitter	clinical testing	Paris Brain Institute, Inserm - ICM	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 04, 2022	This premature translational stop signal has been observed in individuals with hereditary spastic paraplegia (HSP) (PMID: 16534102, 23065789). For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Phe284Profs*45) 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 (rs768595656, gnomAD 0.006%). -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs768595656; hg19: chr16-89595976;