Variant 9-130452225-C-T details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_StrongBS2

The NM_054012.4(ASS1):c.-4C>T variant causes a splice region, 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000307 in 1,614,052 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00037 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00030 ( 3 hom. )

Consequence

ASS1
NM_054012.4 splice_region, 5_prime_UTR

Scores

Splicing: ADA: 0.0004396

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:7B:1

Conservation

PhyloP100: 0.221

Variant links:

Genes affected

ASS1 (HGNC:758): (argininosuccinate synthase 1) The protein encoded by this gene catalyzes the penultimate step of the arginine biosynthetic pathway. There are approximately 10 to 14 copies of this gene including the pseudogenes scattered across the human genome, among which the one located on chromosome 9 appears to be the only functional gene for argininosuccinate synthetase. Mutations in the chromosome 9 copy of this gene cause citrullinemia. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Aug 2012]

ASS1 links:

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.75).

BS2

High Homozygotes in GnomAdExome4 at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ASS1	NM_054012.4 linkuse as main transcript	c.-4C>T		splice_region_variant, 5_prime_UTR_variant	2/15	ENST00000352480.10
ASS1	NM_000050.4 linkuse as main transcript	c.-4C>T		splice_region_variant, 5_prime_UTR_variant	3/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ASS1	ENST00000352480.10 linkuse as main transcript	c.-4C>T		splice_region_variant, 5_prime_UTR_variant	2/15	1	NM_054012.4	P1

Frequencies

GnomAD3 genomes

AF:

0.000381

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000531

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000458

Gnomad ASJ

AF:

0.000864

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00125

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.0158

Gnomad NFE

AF:

0.000206

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000558

AC:

140

AN:

250834

Hom.:

AF XY:

0.000685

AC XY:

AN XY:

135680

show subpopulations

Gnomad AFR exome

AF:

0.000617

Gnomad AMR exome

AF:

0.000695

Gnomad ASJ exome

AF:

0.000497

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00180

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000309

Gnomad OTH exome

AF:

0.00180

GnomAD4 exome

AF:

0.000300

AC:

438

AN:

1461734

Hom.:

Cov.:

AF XY:

0.000402

AC XY:

292

AN XY:

727166

show subpopulations

Gnomad4 AFR exome

AF:

0.000807

Gnomad4 AMR exome

AF:

0.000626

Gnomad4 ASJ exome

AF:

0.000574

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00179

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.000137

Gnomad4 OTH exome

AF:

0.000397

GnomAD4 genome

AF:

0.000374

AC:

AN:

152318

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74484

show subpopulations

Gnomad4 AFR

AF:

0.000529

Gnomad4 AMR

AF:

0.000458

Gnomad4 ASJ

AF:

0.000864

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00125

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000206

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000356

Hom.:

Bravo

AF:

0.000476

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000436

EpiControl

AF:

0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:7Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Citrullinemia type I

Uncertain:5

Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Genetics, Royal Melbourne Hospital	Apr 11, 2023	This sequence change in ASS1 is located in the 5' untranslated region. It introduces an alternative initiation codon and alters the Kozak consensus sequence, which plays an essential role in protein translation initiation. No functional assays have been reported to assess if the variant affects protein translation. The highest population minor allele frequency in the population database gnomAD v2.1 is 0.18% (55/30,574 alleles) in the South Asian population. This variant has been reported as likely pathogenic, a variant of uncertain significance, and likely benign (ClinVar ID: 203632). This variant has been observed with a variant of uncertain significance in an individual with citrullinaemia (PMID: 28111830). Based on the classification scheme RMH Modified ACMG Guidelines v1.6.1, this variant is classified as a VARIANT OF UNCERTAIN SIGNIFICANCE. Following criteria are met: none. -
Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Oct 01, 2021	NM_000050.4(ASS1):c.-4C>T is a 5' non-coding variant classified as a variant of uncertain significance in the context of citrullinemia type 1. c.-4C>T has been observed in a case with relevant disease (PMID: 28111830). Functional assessments of this variant are not available in the literature. c.-4C>T has been observed in population frequency databases (gnomAD: SAS 0.18%). In summary, there is insufficient evidence to classify NM_000050.4(ASS1):c.-4C>T as pathogenic or benign. Please note: this variant was assessed in the context of healthy population screening. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	May 18, 2021	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Jun 21, 2021	- -

not provided

Pathogenic:1Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 29, 2019	Previously reported in association with citrullinemia type I (Engel et al., 2009); Nucleotide substitution has no predicted effect on splicing and is not conserved across species; Alters the Kozak consensus sequence, which plays an important role in the initiation of protein translation; This variant is associated with the following publications: (PMID: 25087612, 19006241) -
Likely pathogenic, flagged submission	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Apr 13, 2023

Variant summary: ASS1 c.-4C>T is located in the untranslated mRNA region upstream of the initiation codon. The variant allele was found at a frequency of 0.00056 in 250834 control chromosomes in the gnomAD database, including 1 homozygotes. This frequency is not significantly higher than estimated for a pathogenic variant in ASS1 causing Citrullinemia Type I (0.00056 vs 0.0041), allowing no conclusion about variant significance. The variant was reported in the literature without strong evidence for causality. To our knowledge, no experimental evidence demonstrating its impact on protein function have been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified as VUS (n=5), Likely Pathogenic (n=1) and Likely Benign (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Citrullinemia

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 08, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.75

CADD

Benign

7.2

DANN

Benign

0.70

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00044

dbscSNV1_RF

Benign

0.040

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over