rs45566933

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS1

The NM_000817.3(GAD1):​c.682A>C​(p.Ile228Leu) variant causes a missense change. The variant allele was found at a frequency of 0.000516 in 1,611,270 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00053 ( 1 hom. )

Consequence

GAD1
NM_000817.3 missense

Scores

1
2
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 5.41

Publications

4 publications found
Variant links:
Genes affected
GAD1 (HGNC:4092): (glutamate decarboxylase 1) This gene encodes one of several forms of glutamic acid decarboxylase, identified as a major autoantigen in insulin-dependent diabetes. The enzyme encoded is responsible for catalyzing the production of gamma-aminobutyric acid from L-glutamic acid. A pathogenic role for this enzyme has been identified in the human pancreas since it has been identified as an autoantigen and an autoreactive T cell target in insulin-dependent diabetes. This gene may also play a role in the stiff man syndrome. Deficiency in this enzyme has been shown to lead to pyridoxine dependency with seizures. Alternative splicing of this gene results in two products, the predominant 67-kD form and a less-frequent 25-kD form. [provided by RefSeq, Jul 2008]
GAD1 Gene-Disease associations (from GenCC):
  • early infantile epileptic encephalopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • developmental and epileptic encephalopathy 89
    Inheritance: AR Classification: STRONG, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)
  • spastic quadriplegic cerebral palsy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • cerebral palsy, spastic quadriplegic, 1
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
  • neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities
    Inheritance: AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.079863876).
BP6
Variant 2-170844088-A-C is Benign according to our data. Variant chr2-170844088-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 332231.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000387 (59/152352) while in subpopulation NFE AF = 0.000661 (45/68036). AF 95% confidence interval is 0.000507. There are 0 homozygotes in GnomAd4. There are 26 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GAD1NM_000817.3 linkc.682A>C p.Ile228Leu missense_variant Exon 7 of 17 ENST00000358196.8 NP_000808.2 Q99259-1A0A0S2Z3V5Q8IVA8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GAD1ENST00000358196.8 linkc.682A>C p.Ile228Leu missense_variant Exon 7 of 17 1 NM_000817.3 ENSP00000350928.3 Q99259-1

Frequencies

GnomAD3 genomes
AF:
0.000388
AC:
59
AN:
152234
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000145
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000327
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:
0.000661
Gnomad OTH
AF:
0.00143
GnomAD2 exomes
AF:
0.000322
AC:
81
AN:
251304
AF XY:
0.000302
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.000376
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000554
Gnomad OTH exome
AF:
0.000490
GnomAD4 exome
AF:
0.000529
AC:
772
AN:
1458918
Hom.:
1
Cov.:
28
AF XY:
0.000486
AC XY:
353
AN XY:
726096
show subpopulations
African (AFR)
AF:
0.0000898
AC:
3
AN:
33418
American (AMR)
AF:
0.000335
AC:
15
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26104
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39640
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86204
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000647
AC:
718
AN:
1109394
Other (OTH)
AF:
0.000581
AC:
35
AN:
60264
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
36
71
107
142
178
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
30
60
90
120
150
<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:
0.000387
AC:
59
AN:
152352
Hom.:
0
Cov.:
32
AF XY:
0.000349
AC XY:
26
AN XY:
74496
show subpopulations
African (AFR)
AF:
0.000144
AC:
6
AN:
41582
American (AMR)
AF:
0.000327
AC:
5
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000661
AC:
45
AN:
68036
Other (OTH)
AF:
0.00142
AC:
3
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.000481
Hom.:
0
Bravo
AF:
0.000476
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000465
AC:
4
ExAC
AF:
0.000264
AC:
32
Asia WGS
AF:
0.000289
AC:
1
AN:
3476
EpiCase
AF:
0.000273
EpiControl
AF:
0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Sep 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

GAD1: BS1 -

Feb 03, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities Uncertain:1Benign:1
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Nov 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Aug 05, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.682A>C (p.I228L) alteration is located in exon 7 (coding exon 6) of the GAD1 gene. This alteration results from a A to C substitution at nucleotide position 682, causing the isoleucine (I) at amino acid position 228 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.075
BayesDel_addAF
Benign
-0.44
T
BayesDel_noAF
Benign
-0.51
CADD
Benign
18
DANN
Benign
0.96
DEOGEN2
Benign
0.28
.;T
Eigen
Benign
0.084
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Benign
0.61
D
LIST_S2
Uncertain
0.86
D;D
M_CAP
Benign
0.0049
T
MetaRNN
Benign
0.080
T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.55
N;N
PhyloP100
5.4
PrimateAI
Pathogenic
0.81
D
PROVEAN
Benign
-0.98
.;N
REVEL
Benign
0.071
Sift
Benign
0.30
.;T
Sift4G
Benign
0.62
T;T
Polyphen
0.0020
.;B
Vest4
0.26
MutPred
0.23
Loss of MoRF binding (P = 0.1715);Loss of MoRF binding (P = 0.1715);
MVP
0.29
MPC
0.59
ClinPred
0.040
T
GERP RS
6.2
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.51
gMVP
0.69
Mutation Taster
=85/15
polymorphism

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: rs45566933; hg19: chr2-171700598; API