NM_020686.6:c.25C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_020686.6(ABAT):​c.25C>T​(p.Arg9Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000734 in 1,607,252 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R9H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000075 ( 0 hom. )

Consequence

ABAT
NM_020686.6 missense

Scores

4
14

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.28

Publications

2 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 Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet
  • 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: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.12967992).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020686.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ABAT
NM_020686.6
MANE Select
c.25C>Tp.Arg9Cys
missense
Exon 2 of 16NP_065737.2
ABAT
NM_001386615.1
c.25C>Tp.Arg9Cys
missense
Exon 2 of 17NP_001373544.1
ABAT
NM_001386616.1
c.25C>Tp.Arg9Cys
missense
Exon 2 of 16NP_001373545.1H3BNQ7

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ABAT
ENST00000268251.13
TSL:1 MANE Select
c.25C>Tp.Arg9Cys
missense
Exon 2 of 16ENSP00000268251.8P80404
ABAT
ENST00000569156.5
TSL:1
c.25C>Tp.Arg9Cys
missense
Exon 2 of 16ENSP00000454963.1H3BNQ7
ABAT
ENST00000566590.5
TSL:1
n.25C>T
non_coding_transcript_exon
Exon 2 of 15ENSP00000455198.1H3BP84

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152134
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000109
AC:
26
AN:
238116
AF XY:
0.000109
show subpopulations
Gnomad AFR exome
AF:
0.0000667
Gnomad AMR exome
AF:
0.000119
Gnomad ASJ exome
AF:
0.000617
Gnomad EAS exome
AF:
0.0000557
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000929
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000749
AC:
109
AN:
1455118
Hom.:
0
Cov.:
31
AF XY:
0.0000691
AC XY:
50
AN XY:
723150
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.0000910
AC:
4
AN:
43948
Ashkenazi Jewish (ASJ)
AF:
0.000618
AC:
16
AN:
25896
East Asian (EAS)
AF:
0.0000505
AC:
2
AN:
39608
South Asian (SAS)
AF:
0.000165
AC:
14
AN:
84654
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52468
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000595
AC:
66
AN:
1109170
Other (OTH)
AF:
0.000116
AC:
7
AN:
60160
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
8
16
23
31
39
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000592
AC:
9
AN:
152134
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41402
American (AMR)
AF:
0.000196
AC:
3
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.000108
Hom.:
0
Bravo
AF:
0.0000529
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000989
AC:
12

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
2
-
Gamma-aminobutyric acid transaminase deficiency (2)
-
1
-
Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.13
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
22
DANN
Uncertain
0.98
DEOGEN2
Benign
0.035
T
Eigen
Benign
-0.32
Eigen_PC
Benign
-0.40
FATHMM_MKL
Benign
0.56
D
LIST_S2
Benign
0.83
T
M_CAP
Benign
0.055
D
MetaRNN
Benign
0.13
T
MetaSVM
Benign
-0.58
T
MutationAssessor
Benign
0.55
N
PhyloP100
3.3
PrimateAI
Benign
0.28
T
PROVEAN
Benign
-0.91
N
REVEL
Uncertain
0.35
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.011
D
Polyphen
0.98
D
Vest4
0.50
MVP
0.87
MPC
0.65
ClinPred
0.053
T
GERP RS
3.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.13
gMVP
0.41
Mutation Taster
=91/9
polymorphism

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: rs201701679; hg19: chr16-8829621; API