7-97869140-G-T

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM2PP2PP3_ModeratePP5_Very_Strong

The NM_001673.5(ASNS):​c.17C>A​(p.Ala6Glu) variant causes a missense change. The variant allele was found at a frequency of 0.00000558 in 1,613,910 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A6V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

ASNS
NM_001673.5 missense

Scores

8
10
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 6.25

Publications

14 publications found
Variant links:
Genes affected
ASNS (HGNC:753): (asparagine synthetase (glutamine-hydrolyzing)) The protein encoded by this gene is involved in the synthesis of asparagine. This gene complements a mutation in the temperature-sensitive hamster mutant ts11, which blocks progression through the G1 phase of the cell cycle at nonpermissive temperature. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, May 2010]
ASNS Gene-Disease associations (from GenCC):
  • congenital microcephaly - severe encephalopathy - progressive cerebral atrophy syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 13 ACMG points.

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 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.8574 (below the threshold of 3.09). Trascript score misZ: 2.3971 (below the threshold of 3.09). GenCC associations: The gene is linked to congenital microcephaly - severe encephalopathy - progressive cerebral atrophy syndrome.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.894
PP5
Variant 7-97869140-G-T is Pathogenic according to our data. Variant chr7-97869140-G-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 91842.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
ASNSNM_001673.5 linkc.17C>A p.Ala6Glu missense_variant Exon 3 of 13 ENST00000394308.8 NP_001664.3 P08243-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ASNSENST00000394308.8 linkc.17C>A p.Ala6Glu missense_variant Exon 3 of 13 1 NM_001673.5 ENSP00000377845.3 P08243-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152128
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251240
AF XY:
0.0000147
show subpopulations
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:
0.00000547
AC:
8
AN:
1461782
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
727162
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1111916
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152128
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74322
show subpopulations
⚠️ 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:
41418
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
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 = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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:
0.0000272
Hom.:
0

ClinVar

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

Submissions by phenotype

not provided Pathogenic:2
Feb 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 6 of the ASNS protein (p.Ala6Glu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with asparagine synthetase deficiency (PMID: 24139043). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 91842). 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 ASNS protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects ASNS function (PMID: 24139043). For these reasons, this variant has been classified as Pathogenic. -

Jun 01, 2016
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The A6E variant in the ASNS gene was reported previously in a French Canadian family in the compound heterozygous state with the R550C variant in three siblings with progressive microcephaly, infantile epilepsy, profound developmental delay, axial hypotonia, and an abnormal brain MRI (Ruzzo et al., 2013). The A6E variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The A6E variant is a non-conservative amino acid substitution, which occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. The A6E variant was reported to impair ASNS gene function by reducing protein expression in HEK and COS cells (Ruzzo et al., 2013). The A6E variant is a strong candidate for a pathogenic variant, however the possibility it may be a rare benign variant cannot be excluded. -

Congenital microcephaly - severe encephalopathy - progressive cerebral atrophy syndrome Pathogenic:1
Oct 16, 2013
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.20
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.78
D;D;D;D;.;.;D;T
Eigen
Pathogenic
0.82
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.96
D;.;.;D;D;D;D;D
M_CAP
Uncertain
0.24
D
MetaRNN
Pathogenic
0.89
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.071
D
MutationAssessor
Pathogenic
3.8
H;H;H;.;.;.;.;.
PhyloP100
6.3
PrimateAI
Pathogenic
0.84
D
PROVEAN
Uncertain
-3.5
D;D;D;D;D;D;D;D
REVEL
Uncertain
0.59
Sift
Uncertain
0.0030
D;D;D;D;D;D;D;.
Sift4G
Uncertain
0.0060
D;D;D;.;.;.;.;.
Polyphen
0.99
D;D;D;.;.;.;.;.
Vest4
0.95
MutPred
0.78
Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);Gain of disorder (P = 0.0597);
MVP
0.73
MPC
1.2
ClinPred
0.98
D
GERP RS
4.3
RBP_binding_hub_radar
1.1
RBP_regulation_power_radar
3.0
Varity_R
0.92
gMVP
0.99
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs398122975; hg19: chr7-97498452; API