rs570490857

Variant summary

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

The NM_020686.6(ABAT):​c.803G>A​(p.Arg268His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,614,098 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

ABAT
NM_020686.6 missense

Scores

8
8
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.11

Publications

0 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: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ABATNM_020686.6 linkc.803G>A p.Arg268His missense_variant Exon 11 of 16 ENST00000268251.13 NP_065737.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABATENST00000268251.13 linkc.803G>A p.Arg268His missense_variant Exon 11 of 16 1 NM_020686.6 ENSP00000268251.8

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152172
Hom.:
0
Cov.:
33
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:
0.000578
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
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251458
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1461808
Hom.:
0
Cov.:
32
AF XY:
0.0000220
AC XY:
16
AN XY:
727208
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000252
AC:
28
AN:
1111964
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
2
4
7
9
11
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:
0.0000197
AC:
3
AN:
152290
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74448
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41568
American (AMR)
AF:
0.00
AC:
0
AN:
15296
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000580
AC:
3
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000189
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Gamma-aminobutyric acid transaminase deficiency Uncertain:1
Aug 31, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine with histidine at codon 268 of the ABAT protein (p.Arg268His). The arginine residue is moderately conserved and there is a small physicochemical difference between arginine and histidine. This variant is present in population databases (rs570490857, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with ABAT-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Pathogenic
0.18
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.65
D;D;.;D;D
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.0
.;D;D;.;D
M_CAP
Uncertain
0.13
D
MetaRNN
Uncertain
0.56
D;D;D;D;D
MetaSVM
Uncertain
0.59
D
MutationAssessor
Pathogenic
3.0
M;M;.;M;.
PhyloP100
8.1
PrimateAI
Uncertain
0.69
T
PROVEAN
Uncertain
-4.1
D;D;D;D;D
REVEL
Pathogenic
0.78
Sift
Uncertain
0.0020
D;D;D;D;D
Sift4G
Uncertain
0.0050
D;D;D;D;D
Vest4
0.55
ClinPred
0.97
D
GERP RS
5.7
Varity_R
0.53
gMVP
0.87
Mutation Taster
=49/51
disease causing

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: rs570490857; hg19: chr16-8862817; COSMIC: COSV51621886; COSMIC: COSV51621886; API