chr16-89529568-TT-C

Variant names:

• chr16-89529568-TT-C
• rs768595656
• NM_003119.4:c.850_851delTTinsC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_003119.4(SPG7):​c.850_851delTTinsC​(p.Phe284ProfsTer45) 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 pathogenic. 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:5
• Conservation: PhyloP100: 7.77
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• hereditary spastic paraplegia 7

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, PanelApp Australia, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)
• autosomal dominant optic atrophy

  Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia
• lateral sclerosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 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 VariationId is 533735.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003119.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPG7	NM_003119.4	MANE Select	c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 17	NP_003110.1	Q9UQ90-1
	SPG7	NM_001363850.1		c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 18	NP_001350779.1	A0A2R8Y3M4
	SPG7	NM_199367.3		c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 10	NP_955399.1	Q9UQ90-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPG7	ENST00000645818.2	MANE Select	c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 17	ENSP00000495795.2	Q9UQ90-1
	SPG7	ENST00000268704.7	TSL:1	c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 17	ENSP00000268704.3	A0A2U3TZH1
	SPG7	ENST00000341316.6	TSL:1	c.850_851delTTinsC	p.Phe284ProfsTer45	frameshift missense	Exon 6 of 10	ENSP00000341157.2	Q9UQ90-2

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

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Hereditary spastic paraplegia 7 (5)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.8
Mutation Taster		=1/199	disease causing (fs/PTC)

Splicing

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

Other links and lift over

dbSNP: rs768595656; hg19: chr16-89595976;