Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate
The NM_003119.4(SPG7):c.1948G>T(p.Asp650Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D650N) has been classified as Pathogenic.
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: Laboratory for Molecular Medicine, G2P, Orphanet, Labcorp Genetics (formerly Invitae)
lateral sclerosis
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
Our verdict: Pathogenic. The variant received 12 ACMG points.
PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_003119.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-89553805-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 220101.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.975
PP5
Variant 16-89553805-G-T is Pathogenic according to our data. Variant chr16-89553805-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1344132.Status of the report is criteria_provided_single_submitter, 1 stars.