rs1553317032

Positions:

• chr2-32128445-TTAATA-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The ENST00000315285.9(SPAST):​c.1215_1219del​(p.Asn405LysfsTer36) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,510 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SPAST ENST00000315285.9 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 8.25

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 Pathogenic. Variant got 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 2-32128445-TTAATA-T is Pathogenic according to our data. Variant chr2-32128445-TTAATA-T is described in ClinVar as [Pathogenic]. Clinvar id is 468562.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPAST	NM_014946.4	c.1215_1219del	p.Asn405LysfsTer36	frameshift_variant	9/17	ENST00000315285.9	NP_055761.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SPAST	ENST00000315285.9	c.1215_1219del	p.Asn405LysfsTer36	frameshift_variant	9/17	1	NM_014946.4	ENSP00000320885	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460510 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 726666

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: 9.00e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Nov 01, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 04, 2023	Frameshift variant predicted to result in nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 12124993, 26671083, 29980238, 17598599, 19289482, 18701882, 17594340, 15841487, 10699187) -

Hereditary spastic paraplegia 4 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Paris Brain Institute, Inserm - ICM	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 20, 2024	This sequence change creates a premature translational stop signal (p.Asn405Lysfs*36) in the SPAST gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SPAST are known to be pathogenic (PMID: 20932283). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with hereditary spastic paraplegia (PMID: 10699187, 15841487, 17594340, 17598599, 18701882, 19289482, 26671083). It has also been observed to segregate with disease in related individuals. This variant is also known as c.1340_1344delTATAA or 1340del5. ClinVar contains an entry for this variant (Variation ID: 468562). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553317032; hg19: chr2-32353514;