16-8775017-C-G

Position:

chr16-8775017-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4BS1_Supporting

The NM_020686.6(ABAT):c.1082C>G(p.Thr361Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

ABAT
NM_020686.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.81

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.31893608).

BS1

Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.00000958 (14/1461892) while in subpopulation AMR AF= 0.000313 (14/44724). AF 95% confidence interval is 0.000189. There are 0 homozygotes in gnomad4_exome. There are 8 alleles in male gnomad4_exome subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABAT	NM_020686.6 linkuse as main transcript	c.1082C>G	p.Thr361Ser	missense_variant	13/16	ENST00000268251.13	NP_065737.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABAT	ENST00000268251.13 linkuse as main transcript	c.1082C>G	p.Thr361Ser	missense_variant	13/16	1	NM_020686.6	ENSP00000268251	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000517

AC:

AN:

251484

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135916

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000376

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461892

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000313

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000330

AC:

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 19, 2022

This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 361 of the ABAT protein (p.Thr361Ser). This variant is present in population databases (rs774473099, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with ABAT-related conditions. ClinVar contains an entry for this variant (Variation ID: 529787). 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

0.15

BayesDel_addAF

Benign

-0.17

BayesDel_noAF

Benign

-0.18

CADD

Benign

DANN

Benign

0.64

DEOGEN2

Uncertain

0.57

D;D;.;D;D

Eigen

Benign

-1.0

Eigen_PC

Benign

-0.86

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.92

.;D;D;.;D

M_CAP

Benign

0.039

MetaRNN

Benign

0.32

T;T;T;T;T

MetaSVM

Benign

-0.41

MutationAssessor

Benign

0.71

N;N;.;N;.

MutationTaster

Benign

1.0

D;D;D;D;D

PrimateAI

Benign

0.48

PROVEAN

Uncertain

-2.4

N;N;N;N;N

REVEL

Uncertain

0.37

Sift

Benign

0.053

T;T;D;T;T

Sift4G

Uncertain

0.057

T;T;T;T;T

Polyphen

0.0030

B;B;.;B;.

Vest4

0.22

MutPred

0.74

Gain of disorder (P = 0.0355);Gain of disorder (P = 0.0355);.;Gain of disorder (P = 0.0355);Gain of disorder (P = 0.0355);

MVP

0.59

MPC

0.29

ClinPred

0.073

GERP RS

3.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.33

gMVP

0.74

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over