chr2-201701087-T-C

Position:

• chr2-201701087-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_020919.4(ALS2):​c.*764A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,280 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: ALS2 NM_020919.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: -0.613

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALS2	NM_020919.4	c.*764A>G		3_prime_UTR_variant	34/34	ENST00000264276.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALS2	ENST00000264276.11	c.*764A>G		3_prime_UTR_variant	34/34	1	NM_020919.4	P4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152162 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152280 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74458

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Amyotrophic lateral sclerosis type 2, juvenile Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

ALS2-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	1.1
DANN	Benign	0.55

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: rs74933581; hg19: chr2-202565810;