Genetic Variant ASS1:c.1194-1G>T (chr9-130500975-G-T) – ACMG Classification: Pathogenic (10 pts)

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PM2

The NM_054012.4(ASS1):c.1194-1G>T variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,450 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ASS1
NM_054012.4 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 7.31

Publications

0 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

ASS1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.7, offset of 25, new splice context is: aggaatatcatcgtctccAGagc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASS1	NM_054012.4 link	c.1194-1G>T		splice_acceptor_variant, intron_variant	Intron 14 of 14	ENST00000352480.10	NP_446464.1
ASS1	NM_000050.4 link	c.1194-1G>T		splice_acceptor_variant, intron_variant	Intron 15 of 15		NP_000041.2

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein
ASS1	ENST00000352480.10 link	c.1194-1G>T	splice_acceptor_variant, intron_variant	Intron 14 of 14	1	NM_054012.4	ENSP00000253004.6
ASS1	ENST00000372393.7 link	c.1194-1G>T	splice_acceptor_variant, intron_variant	Intron 15 of 15	5		ENSP00000361469.2
ASS1	ENST00000372394.5 link	c.1194-1G>T	splice_acceptor_variant, intron_variant	Intron 15 of 15	2		ENSP00000361471.1
ASS1	ENST00000372386.6 link	n.465-1G>T	splice_acceptor_variant, intron_variant	Intron 5 of 5	3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461450

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727046

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33470

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39688

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53252

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111784

Other (OTH)

AF:

0.00

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.60

BayesDel_noAF

Pathogenic

0.21

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.0

.;.;.

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.94

LIST_S2

Benign

0.0

.;.;.

MetaRNN

Benign

0.0

.;.;.

MutationAssessor

Benign

0.0

.;.;.

PhyloP100

7.3

PROVEAN

Benign

0.0

.;.;.

Sift

Pathogenic

0.0

.;.;.

Sift4G

Pathogenic

0.0

.;.;.

Vest4

0.0

GERP RS

4.7

Mutation Taster

=3/97

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.69

Position offset: 8

DS_AL_spliceai

0.98

Position offset: 1

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over