rs878855058

Positions:

• chr2-201757444-CCTCT-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_020919.4(ALS2):​c.1425_1428delAGAG​(p.Gly477fs) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000274 in 1,461,782 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: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ALS2 NM_020919.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.10

Genes affected

ALS2 (HGNC:443): (alsin Rho guanine nucleotide exchange factor ALS2) The protein encoded by this gene contains an ATS1/RCC1-like domain, a RhoGEF domain, and a vacuolar protein sorting 9 (VPS9) domain, all of which are guanine-nucleotide exchange factors that activate members of the Ras superfamily of GTPases. The protein functions as a guanine nucleotide exchange factor for the small GTPase RAB5. The protein localizes with RAB5 on early endosomal compartments, and functions as a modulator for endosomal dynamics. Mutations in this gene result in several forms of juvenile lateral sclerosis and infantile-onset ascending spastic paralysis. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2008]

ALS2 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 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 2-201757444-CCTCT-C is Pathogenic according to our data. Variant chr2-201757444-CCTCT-C is described in ClinVar as [Pathogenic]. Clinvar id is 241308.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALS2	NM_020919.4	c.1425_1428delAGAG	p.Gly477fs	frameshift_variant	5/34	ENST00000264276.11	NP_065970.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALS2	ENST00000264276.11	c.1425_1428delAGAG	p.Gly477fs	frameshift_variant	5/34	1	NM_020919.4	ENSP00000264276.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461782 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727192

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Infantile-onset ascending hereditary spastic paralysis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 22, 2022

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 241308). This premature translational stop signal has been observed in individual(s) with autosomal recessive infantile-onset ascending hereditary spastic paraplegia (PMID: 25302125). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gly477Alafs*19) in the ALS2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ALS2 are known to be pathogenic (PMID: 11586298, 24315819). -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs878855058; hg19: chr2-202622167;