chr16-89544745-C-G

Variant names:

• chr16-89544745-C-G
• rs201482100
• NM_003119.4:c.1422C>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PM5 PP3

The NM_003119.4(SPG7):​c.1422C>G​(p.His474Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H474Y) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SPG7 NM_003119.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0490
• Publications: 0 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: Laboratory for Molecular Medicine, G2P, Orphanet, Labcorp Genetics (formerly Invitae)
• lateral sclerosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr16-89544743-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 566692.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.835

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPG7	NM_003119.4	c.1422C>G	p.His474Gln	missense_variant	Exon 10 of 17	ENST00000645818.2	NP_003110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPG7	ENST00000645818.2	c.1422C>G	p.His474Gln	missense_variant	Exon 10 of 17		NM_003119.4	ENSP00000495795.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461782 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727204

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53352

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111976

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 7 Uncertain:1

Oct 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SPG7 protein function. ClinVar contains an entry for this variant (Variation ID: 1500914). This variant has not been reported in the literature in individuals affected with SPG7-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 474 of the SPG7 protein (p.His474Gln). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Benign	6.3
DANN	Benign	0.88
DEOGEN2	Pathogenic	0.81	.;.;D;.;.;.;.;.
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.51
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.96	D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.13	D
MutationAssessor	Benign	0.63	.;.;N;.;.;.;.;.
PhyloP100		-0.049
PrimateAI	Uncertain	0.77	T
REVEL	Pathogenic	0.67
Polyphen		0.94	.;.;P;.;.;.;.;.
MutPred		0.61		.;.;Loss of catalytic residue at D478 (P = 0.094);Loss of catalytic residue at D478 (P = 0.094);Loss of catalytic residue at D478 (P = 0.094);Loss of catalytic residue at D478 (P = 0.094);.;.;
MVP		0.91
MPC		0.80
ClinPred		0.85	D
GERP RS		-3.4
Varity_R		0.78
gMVP		0.66

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs201482100; hg19: chr16-89611153;