rs148143485

Variant names:

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020686.6(ABAT):c.684G>A(p.Thr228Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00137 in 1,614,148 control chromosomes in the GnomAD database, including 36 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.00089 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0014 ( 36 hom. )

Consequence

ABAT
NM_020686.6 synonymous

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: -1.11

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

ABAT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -21 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.58).

BP6

Variant 16-8768841-G-A is Benign according to our data. Variant chr16-8768841-G-A is described in ClinVar as Benign. ClinVar VariationId is 193917.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-1.11 with no splicing effect.

BS1

Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000887 (135/152284) while in subpopulation SAS AF = 0.017 (82/4828). AF 95% confidence interval is 0.014. There are 0 homozygotes in GnomAd4. There are 92 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAdExome4 at 36 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABAT	NM_020686.6 link	c.684G>A	p.Thr228Thr	synonymous_variant	Exon 11 of 16	ENST00000268251.13	NP_065737.2	P80404X5D8S1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABAT	ENST00000268251.13 link	c.684G>A	p.Thr228Thr	synonymous_variant	Exon 11 of 16	1	NM_020686.6	ENSP00000268251.8		P80404

Frequencies

GnomAD3 genomes

AF:

0.000894

AC:

136

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000589

Gnomad ASJ

AF:

0.00115

Gnomad EAS

AF:

0.00289

Gnomad SAS

AF:

0.0172

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00633

Gnomad NFE

AF:

0.000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00296

AC:

744

AN:

251462

AF XY:

0.00388

show subpopulations

Gnomad AFR exome

AF:

0.000554

Gnomad AMR exome

AF:

0.000347

Gnomad ASJ exome

AF:

0.00109

Gnomad EAS exome

AF:

0.00299

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000193

Gnomad OTH exome

AF:

0.00179

GnomAD4 exome

AF:

0.00142

AC:

2074

AN:

1461864

Hom.:

Cov.:

AF XY:

0.00203

AC XY:

1479

AN XY:

727230

show subpopulations

African (AFR)

AF:

0.000358

AC:

AN:

33480

American (AMR)

AF:

0.000537

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.000727

AC:

AN:

26136

East Asian (EAS)

AF:

0.00176

AC:

AN:

39698

South Asian (SAS)

AF:

0.0200

AC:

1727

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00312

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000818

AC:

AN:

1112004

Other (OTH)

AF:

0.00185

AC:

112

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.472

Heterozygous variant carriers

185

370

555

740

925

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

112

140

<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:

0.000887

AC:

135

AN:

152284

Hom.:

Cov.:

AF XY:

0.00124

AC XY:

AN XY:

74472

show subpopulations

African (AFR)

AF:

0.000313

AC:

AN:

41548

American (AMR)

AF:

0.000588

AC:

AN:

15296

Ashkenazi Jewish (ASJ)

AF:

0.00115

AC:

AN:

3472

East Asian (EAS)

AF:

0.00289

AC:

AN:

5182

South Asian (SAS)

AF:

0.0170

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00680

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000147

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.504

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000336

Hom.:

Bravo

AF:

0.000540

Asia WGS

AF:

0.0120

AC:

AN:

3478

EpiCase

AF:

0.000327

EpiControl

AF:

0.000296

ClinVar

Significance: Benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:2

Oct 23, 2019

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 19, 2015

Eurofins Ntd Llc (ga)

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Gamma-aminobutyric acid transaminase deficiency

Benign:2

Jan 12, 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. -

Jan 22, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.58

CADD

Benign

3.1

(source)

DANN

Benign

0.73

PhyloP100

-1.1

Mutation Taster

=99/1

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over