rs886039853

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PP2PP3_StrongPP5_Very_Strong

The NM_054012.4(ASS1):​c.851C>T​(p.Thr284Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,642 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ASS1
NM_054012.4 missense

Scores

14
3
2

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:3O:1

Conservation

PhyloP100: 7.38

Publications

2 publications found
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 Gene-Disease associations (from GenCC):
  • citrullinemia type I
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health, G2P
  • acute neonatal citrullinemia type I
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • adult-onset citrullinemia type I
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_054012.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 49 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Gene score misZ: 0.75759 (below the threshold of 3.09). Trascript score misZ: 1.8061 (below the threshold of 3.09). GenCC associations: The gene is linked to citrullinemia type I, adult-onset citrullinemia type I, acute neonatal citrullinemia type I.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.992
PP5
Variant 9-130489345-C-T is Pathogenic according to our data. Variant chr9-130489345-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 265961.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ASS1NM_054012.4 linkc.851C>T p.Thr284Ile missense_variant Exon 12 of 15 ENST00000352480.10 NP_446464.1 P00966Q5T6L4
ASS1NM_000050.4 linkc.851C>T p.Thr284Ile missense_variant Exon 13 of 16 NP_000041.2 P00966Q5T6L4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASS1ENST00000352480.10 linkc.851C>T p.Thr284Ile missense_variant Exon 12 of 15 1 NM_054012.4 ENSP00000253004.6 P00966

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151872
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000242
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
AF:
6.84e-7
AC:
1
AN:
1461770
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
727182
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53340
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111992
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151872
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74126
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41316
American (AMR)
AF:
0.00
AC:
0
AN:
15244
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4800
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10552
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68004
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:3Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Citrullinemia type I Pathogenic:2Other:1
-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Mar 18, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 18, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Citrullinemia Pathogenic:1
Dec 11, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 284 of the ASS1 protein (p.Thr284Ile). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of ASS1-related conditions (PMID: 19006241; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 265961). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ASS1 protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;D;D
Eigen
Pathogenic
0.93
Eigen_PC
Pathogenic
0.81
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.84
.;.;T
M_CAP
Pathogenic
0.71
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.8
H;H;H
PhyloP100
7.4
PrimateAI
Pathogenic
0.87
D
PROVEAN
Pathogenic
-5.1
D;D;D
REVEL
Pathogenic
0.98
Sift
Uncertain
0.0010
D;D;D
Sift4G
Pathogenic
0.0010
D;D;D
Polyphen
1.0
D;D;D
Vest4
0.93
MutPred
0.92
Loss of catalytic residue at T284 (P = 0.075);Loss of catalytic residue at T284 (P = 0.075);Loss of catalytic residue at T284 (P = 0.075);
MVP
0.98
MPC
0.97
ClinPred
1.0
D
GERP RS
4.5
Varity_R
0.95
gMVP
0.94
Mutation Taster
=0/100
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs886039853; hg19: chr9-133364732; API