rs1553316810

Positions:

• chr2-32126969-C-A
• chr2-32126969-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_014946.4(SPAST):​c.1120C>A​(p.Pro374Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SPAST NM_014946.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.32

Genes affected

SPAST (HGNC:11233): (spastin) This gene encodes a member of the AAA (ATPases associated with a variety of cellular activities) protein 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. The use of alternative translational initiation sites in this gene results in a single transcript variant that can produce isoforms that differ in the length of their N-terminus and which thereby differ in the efficiency of their export from the nucleus to the cytoplasm. In addition, alternative splicing results in multiple transcript variants that encode isoforms that differ in other protein regions as well. One isoform of this gene has been shown to be a microtubule-severing enzyme that regulates microtubule abundance, mobility, and plus-end distribution. Mutations in this gene cause the most frequent form of autosomal dominant spastic paraplegia 4. [provided by RefSeq, May 2018]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPAST	NM_014946.4	c.1120C>A	p.Pro374Thr	missense_variant	8/17	ENST00000315285.9	NP_055761.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPAST	ENST00000315285.9	c.1120C>A	p.Pro374Thr	missense_variant	8/17	1	NM_014946.4	ENSP00000320885	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460064 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 726498

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: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D;D;.;.;.;.;.;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;D;D;.;D;D;D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.1	M;M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-7.7	D;.;D;.;.;.;.;.
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0020	D;.;D;.;.;.;.;.
Sift4G	Pathogenic	0.0	D;D;D;.;.;.;.;.
Polyphen		1.0	D;D;.;.;.;.;.;.
Vest4		0.95
MutPred		0.85		Gain of catalytic residue at P374 (P = 0.057);Gain of catalytic residue at P374 (P = 0.057);.;.;.;.;.;.;
MVP		0.92
MPC		2.4
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.92
gMVP		0.93

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553316810; hg19: chr2-32352038;