1-2025531-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 4P and 4B. PP3_StrongBS2

The NM_000815.5(GABRD):​c.263C>T​(p.Thr88Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000105 in 1,612,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. T88T) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

GABRD
NM_000815.5 missense

Scores

13
5
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.75

Publications

1 publications found
Variant links:
Genes affected
GABRD (HGNC:4084): (gamma-aminobutyric acid type A receptor subunit delta) Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian brain where it acts at GABA-A receptors, which are ligand-gated chloride channels. Chloride conductance of these channels can be modulated by agents such as benzodiazepines that bind to the GABA-A receptor. The GABA-A receptor is generally pentameric and there are five types of subunits: alpha, beta, gamma, delta, and rho. This gene encodes the delta subunit. Mutations in this gene have been associated with susceptibility to generalized epilepsy with febrile seizures, type 5. Alternatively spliced transcript variants have been described for this gene, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]
GABRD Gene-Disease associations (from GenCC):
  • complex neurodevelopmental disorder
    Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
  • epilepsy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • epilepsy, idiopathic generalized, susceptibility to, 10
    Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.941
BS2
High AC in GnomAdExome4 at 15 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GABRDNM_000815.5 linkc.263C>T p.Thr88Met missense_variant Exon 4 of 9 ENST00000378585.7 NP_000806.2 O14764A8K496
GABRDXM_017000936.2 linkc.968C>T p.Thr323Met missense_variant Exon 3 of 8 XP_016856425.1
GABRDXM_011541194.4 linkc.302C>T p.Thr101Met missense_variant Exon 4 of 9 XP_011539496.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GABRDENST00000378585.7 linkc.263C>T p.Thr88Met missense_variant Exon 4 of 9 1 NM_000815.5 ENSP00000367848.4 O14764

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152258
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000319
AC:
8
AN:
250536
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.0000618
Gnomad AMR exome
AF:
0.000174
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.0000103
AC:
15
AN:
1460586
Hom.:
0
Cov.:
33
AF XY:
0.00000688
AC XY:
5
AN XY:
726620
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.000134
AC:
6
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52306
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111858
Other (OTH)
AF:
0.00
AC:
0
AN:
60374
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000131
AC:
2
AN:
152258
Hom.:
0
Cov.:
34
AF XY:
0.0000269
AC XY:
2
AN XY:
74390
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41468
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.000675
Hom.:
0
Bravo
AF:
0.0000453
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000165
AC:
2
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Feb 21, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.263C>T (p.T88M) alteration is located in exon 4 (coding exon 4) of the GABRD gene. This alteration results from a C to T substitution at nucleotide position 263, causing the threonine (T) at amino acid position 88 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Idiopathic generalized epilepsy Uncertain:1
Oct 17, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 88 of the GABRD protein (p.Thr88Met). This variant is present in population databases (rs373508468, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with GABRD-related conditions. ClinVar contains an entry for this variant (Variation ID: 460008). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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
Pathogenic
0.72
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.74
D;.;.;.;.
Eigen
Pathogenic
0.71
Eigen_PC
Uncertain
0.66
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
D;D;D;D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.94
D;D;D;D;D
MetaSVM
Uncertain
0.35
D
MutationAssessor
Uncertain
2.3
M;.;.;.;.
PhyloP100
4.7
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-5.3
D;.;.;.;.
REVEL
Pathogenic
0.86
Sift
Pathogenic
0.0
D;.;.;.;.
Sift4G
Pathogenic
0.0
D;.;.;.;.
Polyphen
1.0
D;.;.;.;.
Vest4
0.87
MVP
0.82
MPC
1.9
ClinPred
0.94
D
GERP RS
4.4
PromoterAI
0.025
Neutral
Varity_R
0.85
gMVP
0.72
Mutation Taster
=48/52
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs373508468; hg19: chr1-1956970; COSMIC: COSV66080758; COSMIC: COSV66080758; API