rs781331391

Positions:

• chr7-66089180-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP5

The ENST00000304874.14(ASL):​c.918+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.0000048 in 1,459,392 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: ASL ENST00000304874.14 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 3.99

Genes affected

ASL (HGNC:746): (argininosuccinate lyase) This gene encodes a member of the lyase 1 family. The encoded protein forms a cytosolic homotetramer and primarily catalyzes the reversible hydrolytic cleavage of argininosuccinate into arginine and fumarate, an essential step in the liver in detoxifying ammonia via the urea cycle. Mutations in this gene result in the autosomal recessive disorder argininosuccinic aciduria, or argininosuccinic acid lyase deficiency. A nontranscribed pseudogene is also located on the long arm of chromosome 22. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-66089180-G-A is Pathogenic according to our data. Variant chr7-66089180-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 554215.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ASL	NM_000048.4	c.918+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000304874.14	NP_000039.2
ASL	NM_001024943.2	c.918+5G>A		splice_donor_5th_base_variant, intron_variant			NP_001020114.1
ASL	NM_001024944.2	c.918+5G>A		splice_donor_5th_base_variant, intron_variant			NP_001020115.1
ASL	NM_001024946.2	c.840+5G>A		splice_donor_5th_base_variant, intron_variant			NP_001020117.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ASL	ENST00000304874.14	c.918+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_000048.4	ENSP00000307188	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000160 AC: 4 AN: 249232 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135478

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

Gnomad SAS exome AF: 0.0000980

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000480 AC: 7 AN: 1459392 Hom.: 0 Cov.: 35 AF XY: 0.00000689 AC XY: 5 AN XY: 726126

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Argininosuccinate lyase deficiency Pathogenic:1 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 03, 2023	For these reasons, this variant has been classified as Pathogenic. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 554215). This variant has been observed in individual(s) with clinical features of argininosuccinate lyase deficiency (PMID: 24166829; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs781331391, gnomAD 0.01%). This sequence change falls in intron 12 of the ASL gene. It does not directly change the encoded amino acid sequence of the ASL protein. It affects a nucleotide within the consensus splice site. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Sep 29, 2017	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.17
CADD	Benign	23
DANN	Uncertain	0.98
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.85		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.32		Position offset: -19
DS_DL_spliceai		0.85		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs781331391; hg19: chr7-65554167;