NM_054012.4:c.970+5G>A

Variant names:

• chr9-130489469-G-A
• rs372128852
• NM_054012.4:c.970+5G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PS3 PM2 PP3_Strong PP5_Very_Strong

The NM_054012.4(ASS1):​c.970+5G>A variant causes a splice region, intron change. The variant allele was found at a frequency of 0.0000161 in 1,613,932 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 Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001338489: The variant allele was found at a frequency of 1.6e-05 in 251104 control chromosomes (gnomAD). c.970+5G>A has been reported in the literature in multiple individuals affected with Citrullinemia Type I (e.g. Kobayashi_1995, Haberle_2002, Gao_2003, Diez-Fernandez_2016). These data indicate that the variant is very likely to be associated with disease. Four other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. no; SCV004030542: Published functional studies demonstrate that the variant results in 132 bp deletion in exon 13 (Kobayashi et al., 1995);".

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: ASS1 NM_054012.4 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11
• Conservation: PhyloP100: 5.54
• Publications: 2 publications found

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 Gene-Disease associations (from GenCC):

• citrullinemia type I

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, Myriad Women’s Health
• acute neonatal citrullinemia type I

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• adult-onset citrullinemia type I

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001338489: The variant allele was found at a frequency of 1.6e-05 in 251104 control chromosomes (gnomAD). c.970+5G>A has been reported in the literature in multiple individuals affected with Citrullinemia Type I (e.g. Kobayashi_1995, Haberle_2002, Gao_2003, Diez-Fernandez_2016). These data indicate that the variant is very likely to be associated with disease. Four other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. no; SCV004030542: Published functional studies demonstrate that the variant results in 132 bp deletion in exon 13 (Kobayashi et al., 1995)
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 9-130489469-G-A is Pathogenic according to our data. Variant chr9-130489469-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 265962.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_054012.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ASS1	NM_054012.4	MANE Select	c.970+5G>A		splice_region intron	N/A	NP_446464.1	Q5T6L4
	ASS1	NM_000050.4		c.970+5G>A		splice_region intron	N/A	NP_000041.2	P00966

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ASS1	ENST00000352480.10	TSL:1 MANE Select	c.970+5G>A		splice_region intron	N/A	ENSP00000253004.6	P00966
	ASS1	ENST00000852201.1		c.1165+5G>A		splice_region intron	N/A	ENSP00000522260.1
	ASS1	ENST00000852207.1		c.1093+5G>A		splice_region intron	N/A	ENSP00000522266.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152118 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251104 AF XY: 0.0000221

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000164 AC: 24 AN: 1461814 Hom.: 0 Cov.: 33 AF XY: 0.0000165 AC XY: 12 AN XY: 727214

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53380

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000189 AC: 21 AN: 1111984

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152118 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74284

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41416

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10598

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68032

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000037155), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000436 Hom.: 0

Bravo AF: 0.00000756

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
8	-	-	Citrullinemia type I (8)
1	-	-	Citrullinemia (1)
1	-	-	not provided (1)
1	-	-	See cases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.37
CADD	Benign	5.8
DANN	Benign	0.91
PhyloP100		5.5
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.92		Position offset: -5

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

Other links and lift over

dbSNP: rs372128852; hg19: chr9-133364856;