2-32063857-A-G

Variant names:

• chr2-32063857-A-G
• NM_014946.4:c.26A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_014946.4(SPAST):​c.26A>G​(p.Lys9Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. K9K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SPAST NM_014946.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.60
• Publications: 0 publications found

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]

SPAST Gene-Disease associations (from GenCC):

• hereditary spastic paraplegia 4

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Illumina, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics, Orphanet
• Charlevoix-Saguenay spastic ataxia

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• neurodevelopmental disorder

  Inheritance: AD Classification: STRONG Submitted by: G2P
• SPAST-related motor disorder

  Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 148 curated pathogenic missense variants (we use a threshold of 10). The gene has 21 curated benign missense variants. Gene score misZ: 1.2438 (below the threshold of 3.09). Trascript score misZ: 0.22274 (below the threshold of 3.09). GenCC associations: The gene is linked to hereditary spastic paraplegia 4, SPAST-related motor disorder, Charlevoix-Saguenay spastic ataxia, neurodevelopmental disorder.
• BP4: Computational evidence support a benign effect (MetaRNN=0.32950065).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_014946.4. 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
	SPAST	NM_014946.4	MANE Select	c.26A>G	p.Lys9Arg	missense	Exon 1 of 17	NP_055761.2
	SPAST	NM_001363823.2		c.26A>G	p.Lys9Arg	missense	Exon 1 of 17	NP_001350752.1	A0A2U3TZR0
	SPAST	NM_199436.2		c.26A>G	p.Lys9Arg	missense	Exon 1 of 16	NP_955468.1	E5KRP6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SPAST	ENST00000315285.9	TSL:1 MANE Select	c.26A>G	p.Lys9Arg	missense	Exon 1 of 17	ENSP00000320885.3	Q9UBP0-1
	SPAST	ENST00000621856.2	TSL:1	c.26A>G	p.Lys9Arg	missense	Exon 1 of 17	ENSP00000482496.2	A0A2U3TZR0
	SPAST	ENST00000713716.1		c.26A>G	p.Lys9Arg	missense	Exon 1 of 18	ENSP00000519019.1	A0AAQ5BGQ0

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Hereditary spastic paraplegia 4 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Uncertain	0.060	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	23
DANN	Benign	0.97
DEOGEN2	Benign	0.14	T
Eigen	Benign	-0.25
Eigen_PC	Benign	-0.16
FATHMM_MKL	Benign	0.61	D
LIST_S2	Benign	0.68	T
M_CAP	Pathogenic	0.98	D
MetaRNN	Benign	0.33	T
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	0.69	N
PhyloP100		3.6
PrimateAI	Pathogenic	0.94	D
PROVEAN	Benign	0.39	N
REVEL	Uncertain	0.33
Sift	Uncertain	0.021	D
Sift4G	Benign	0.061	T
Polyphen		0.42	B
Vest4		0.31
MutPred		0.25		Loss of glycosylation at K9 (P = 0.052)
MVP		0.71
MPC		0.10
ClinPred		0.45	T
GERP RS		4.0
PromoterAI		0.15	Neutral
Varity_R		0.27
gMVP		0.12
Mutation Taster		=66/34	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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

hg19: chr2-32288926;