rs724159992

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_020686.6(ABAT):​c.275G>A​(p.Arg92Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,020 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 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

ABAT
NM_020686.6 missense

Scores

9
3
7

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.96

Publications

13 publications found
Variant links:
Genes affected
ABAT (HGNC:23): (4-aminobutyrate aminotransferase) 4-aminobutyrate aminotransferase (ABAT) is responsible for catabolism of gamma-aminobutyric acid (GABA), an important, mostly inhibitory neurotransmitter in the central nervous system, into succinic semialdehyde. The active enzyme is a homodimer of 50-kD subunits complexed to pyridoxal-5-phosphate. The protein sequence is over 95% similar to the pig protein. GABA is estimated to be present in nearly one-third of human synapses. ABAT in liver and brain is controlled by 2 codominant alleles with a frequency in a Caucasian population of 0.56 and 0.44. The ABAT deficiency phenotype includes psychomotor retardation, hypotonia, hyperreflexia, lethargy, refractory seizures, and EEG abnormalities. Multiple alternatively spliced transcript variants encoding the same protein isoform have been found for this gene. [provided by RefSeq, Jul 2008]
ABAT Gene-Disease associations (from GenCC):
  • GABA aminotransaminase deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia, Orphanet, G2P
  • genetic developmental and epileptic encephalopathy
    Inheritance: AR Classification: MODERATE Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.956
PP5
Variant 16-8750498-G-A is Pathogenic according to our data. Variant chr16-8750498-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 162036.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
ABATNM_020686.6 linkc.275G>A p.Arg92Gln missense_variant Exon 5 of 16 ENST00000268251.13 NP_065737.2 P80404X5D8S1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABATENST00000268251.13 linkc.275G>A p.Arg92Gln missense_variant Exon 5 of 16 1 NM_020686.6 ENSP00000268251.8 P80404

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461830
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727212
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
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:
0.000173
AC:
1
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111964
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.512
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000131
AC:
2
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41444
American (AMR)
AF:
0.0000655
AC:
1
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Gamma-aminobutyric acid transaminase deficiency Pathogenic:4
Sep 07, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 2014
Bonnen Lab, Baylor College of Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

clinical and in vitro studies -

Feb 01, 2010
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Feb 07, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 92 of the ABAT protein (p.Arg92Gln). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with GABA transaminase deficiency (PMID: 20052547, 30617166). 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: 162036). 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 not expected to disrupt ABAT protein function with a negative 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
Benign
0.20
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.33
CADD
Pathogenic
28
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.29
T;T;.;T;T
Eigen
Pathogenic
0.79
Eigen_PC
Pathogenic
0.81
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.99
.;D;D;.;D
M_CAP
Benign
0.063
D
MetaRNN
Pathogenic
0.96
D;D;D;D;D
MetaSVM
Uncertain
0.29
D
MutationAssessor
Uncertain
2.3
M;M;.;M;.
PhyloP100
10
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.0
N;N;N;N;N
REVEL
Pathogenic
0.74
Sift
Benign
0.21
T;T;T;T;T
Sift4G
Benign
0.38
T;T;T;T;T
Polyphen
1.0
D;D;.;D;.
Vest4
0.92
MutPred
0.86
Gain of phosphorylation at Y97 (P = 0.2414);Gain of phosphorylation at Y97 (P = 0.2414);.;Gain of phosphorylation at Y97 (P = 0.2414);Gain of phosphorylation at Y97 (P = 0.2414);
MVP
0.91
MPC
0.47
ClinPred
0.95
D
GERP RS
5.9
Varity_R
0.43
gMVP
0.79
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: rs724159992; hg19: chr16-8844355; COSMIC: COSV51621049; COSMIC: COSV51621049; API