2-32141890-ATTT-ATTTTTT

Variant names:

• chr2-32141890-A-ATTT
• NM_014946.4:c.1494-5_1494-3dupTTT

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_014946.4(SPAST):​c.1494-5_1494-3dupTTT variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000905 in 1,105,416 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 9.0e-7 (0 hom.)
• Consequence: SPAST NM_014946.4 splice_acceptor, intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.175

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 Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.023230687 fraction of the gene. Cryptic splice site detected, with MaxEntScore 9.3, offset of 0 (no position change), new splice context is: tggattttttttttttttAGgcg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPAST	NM_014946.4	c.1494-5_1494-3dupTTT		splice_acceptor_variant, intron_variant	Intron 12 of 16	ENST00000315285.9	NP_055761.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPAST	ENST00000315285.9	c.1494-14_1494-13insTTT		intron_variant	Intron 12 of 16	1	NM_014946.4	ENSP00000320885.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 9.05e-7 AC: 1 AN: 1105416 Hom.: 0 Cov.: 24 AF XY: 0.00000182 AC XY: 1 AN XY: 550016

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: 0.0000156

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-32366959;