NM_020686.6:c.1147C>T

Variant summary

Our verdict is Benign. The variant received -18 ACMG points: 0P and 18B. BP4_ModerateBP6_Very_StrongBA1

The NM_020686.6(ABAT):​c.1147C>T​(p.Leu383Leu) variant causes a synonymous change. The variant allele was found at a frequency of 0.00503 in 1,614,232 control chromosomes in the GnomAD database, including 382 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. L383L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.027 ( 183 hom., cov: 32)
Exomes 𝑓: 0.0028 ( 199 hom. )

Consequence

ABAT
NM_020686.6 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:5

Conservation

PhyloP100: 5.07

Publications

1 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: Benign. The variant received -18 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.34).
BP6
Variant 16-8776368-C-T is Benign according to our data. Variant chr16-8776368-C-T is described in ClinVar as Benign. ClinVar VariationId is 321085.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BA1
GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0903 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ABATNM_020686.6 linkc.1147C>T p.Leu383Leu synonymous_variant Exon 14 of 16 ENST00000268251.13 NP_065737.2 P80404X5D8S1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABATENST00000268251.13 linkc.1147C>T p.Leu383Leu synonymous_variant Exon 14 of 16 1 NM_020686.6 ENSP00000268251.8 P80404

Frequencies

GnomAD3 genomes
AF:
0.0266
AC:
4051
AN:
152230
Hom.:
183
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0929
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00942
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000413
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00633
Gnomad NFE
AF:
0.000309
Gnomad OTH
AF:
0.0148
GnomAD2 exomes
AF:
0.00689
AC:
1732
AN:
251458
AF XY:
0.00505
show subpopulations
Gnomad AFR exome
AF:
0.0916
Gnomad AMR exome
AF:
0.00523
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000308
Gnomad OTH exome
AF:
0.00407
GnomAD4 exome
AF:
0.00278
AC:
4067
AN:
1461884
Hom.:
199
Cov.:
32
AF XY:
0.00236
AC XY:
1718
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.0985
AC:
3297
AN:
33478
American (AMR)
AF:
0.00577
AC:
258
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000104
AC:
9
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00243
AC:
14
AN:
5768
European-Non Finnish (NFE)
AF:
0.000128
AC:
142
AN:
1112012
Other (OTH)
AF:
0.00575
AC:
347
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
255
510
766
1021
1276
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
102
204
306
408
510
<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:
0.0266
AC:
4055
AN:
152348
Hom.:
183
Cov.:
32
AF XY:
0.0249
AC XY:
1853
AN XY:
74498
show subpopulations
African (AFR)
AF:
0.0928
AC:
3855
AN:
41562
American (AMR)
AF:
0.00941
AC:
144
AN:
15310
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.000414
AC:
2
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00680
AC:
2
AN:
294
European-Non Finnish (NFE)
AF:
0.000309
AC:
21
AN:
68042
Other (OTH)
AF:
0.0147
AC:
31
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
192
384
575
767
959
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
42
84
126
168
210
<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:
0.0130
Hom.:
64
Bravo
AF:
0.0298
Asia WGS
AF:
0.00433
AC:
16
AN:
3478
EpiCase
AF:
0.000436
EpiControl
AF:
0.000296

ClinVar

Significance: Benign
Submissions summary: Benign:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:3
Aug 24, 2017
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Mar 16, 2016
Mayo Clinic Laboratories, Mayo Clinic
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Gamma-aminobutyric acid transaminase deficiency Benign:2
Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.34
CADD
Benign
8.7
DANN
Benign
0.87
PhyloP100
5.1
Mutation Taster
=62/38
polymorphism (auto)

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: rs2229158; hg19: chr16-8870225; API