rs104893615

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PP2PP5_Very_Strong

The NM_001298.3(CNGA3):​c.1669G>A​(p.Gly557Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000787 in 1,614,064 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. G557G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000075 ( 0 hom. )

Consequence

CNGA3
NM_001298.3 missense

Scores

16
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8U:1

Conservation

PhyloP100: 9.60

Publications

15 publications found
Variant links:
Genes affected
CNGA3 (HGNC:2150): (cyclic nucleotide gated channel subunit alpha 3) This gene encodes a member of the cyclic nucleotide-gated cation channel protein family which is required for normal vision and olfactory signal transduction. Mutations in this gene are associated with achromatopsia (rod monochromacy) and color blindness. Two alternatively spliced transcripts encoding different isoforms have been described. [provided by RefSeq, Jul 2008]
CNGA3 Gene-Disease associations (from GenCC):
  • achromatopsia 2
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Illumina, PanelApp Australia
  • CNGA3-related retinopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • cone-rod dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • achromatopsia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_001298.3
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 105 curated pathogenic missense variants (we use a threshold of 10). The gene has 14 curated benign missense variants. Trascript score misZ: 0.49806 (below the threshold of 3.09). GenCC associations: The gene is linked to achromatopsia 2, CNGA3-related retinopathy, cone-rod dystrophy, achromatopsia.
PP5
Variant 2-98396839-G-A is Pathogenic according to our data. Variant chr2-98396839-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 9476.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CNGA3NM_001298.3 linkc.1669G>A p.Gly557Arg missense_variant Exon 8 of 8 ENST00000272602.7 NP_001289.1 Q16281-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CNGA3ENST00000272602.7 linkc.1669G>A p.Gly557Arg missense_variant Exon 8 of 8 1 NM_001298.3 ENSP00000272602.2 Q16281-1
CNGA3ENST00000436404.6 linkc.1615G>A p.Gly539Arg missense_variant Exon 7 of 7 1 ENSP00000410070.2 Q16281-2
CNGA3ENST00000409937.1 linkn.1822G>A non_coding_transcript_exon_variant Exon 8 of 8 2

Frequencies

GnomAD3 genomes
AF:
0.000112
AC:
17
AN:
152180
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00432
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:
0.000139
AC:
35
AN:
251330
AF XY:
0.0000957
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00228
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.000814
GnomAD4 exome
AF:
0.0000752
AC:
110
AN:
1461884
Hom.:
0
Cov.:
31
AF XY:
0.0000701
AC XY:
51
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000671
AC:
3
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00298
AC:
78
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1112012
Other (OTH)
AF:
0.000248
AC:
15
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
10
20
29
39
49
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:
0.000112
AC:
17
AN:
152180
Hom.:
0
Cov.:
32
AF XY:
0.0000942
AC XY:
7
AN XY:
74342
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41436
American (AMR)
AF:
0.0000654
AC:
1
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00432
AC:
15
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
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

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:
0.000138
Hom.:
0
Bravo
AF:
0.0000831
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000741
AC:
9
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Achromatopsia 2 Pathogenic:2
Jul 01, 1998
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Mar 06, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:2
Nov 27, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect with alteration of cGMP sensitivity, reduced calcium influx, and decreased cell surface expression compared to wild type (PMID: 18521937); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 11536077, 32531858, 31964843, 9662398, 25616768, 17693388, 18521937, 31456290, 31980526, 38219857) -

Oct 26, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 557 of the CNGA3 protein (p.Gly557Arg). This variant is present in population databases (rs104893615, gnomAD 0.3%). This missense change has been observed in individual(s) with achromatopsia (PMID: 17265047, 18521937, 25616768; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 9476). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CNGA3 protein function with a positive predictive value of 95%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on CNGA3 function (PMID: 17693388, 18521937). For these reasons, this variant has been classified as Pathogenic. -

Retinal dystrophy Pathogenic:2
Jan 16, 2019
Blueprint Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 2021
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Pathogenic:1
Aug 28, 2021
Ambry Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1669G>A (p.G557R) alteration is located in exon 8 (coding exon 7) of the CNGA3 gene. This alteration results from a G to A substitution at nucleotide position 1669, causing the glycine (G) at amino acid position 557 to be replaced by an arginine (R). Based on data from gnomAD, the A allele has an overall frequency of 0.01% (40/282722) total alleles studied. The highest observed frequency was 0.27% (28/10360) of Ashkenazi Jewish alleles. This alteration is one of the most common founder mutations in the Israeli population (Sharon, 2020). It has been reported in association with achromatopsia and other cone photoreceptor disorders in homozygotes and in heterozygotes with an additional CNGA3 alteration (Kohl, 1998; Wissinger, 2001; Wiszniewski, 2007; Reuter, 2008; Zelinger 2015; Matet, 2018). This amino acid position is highly conserved in available vertebrate species. This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as likely pathogenic. -

Achromatopsia Pathogenic:1
Jun 23, 2019
Sharon lab, Hadassah-Hebrew University Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

not specified Uncertain:1
Oct 30, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:flagged submission
Collection Method:clinical testing

The Gly557Arg variant in CNGA3 has been identified in 1 compound heterozygous individual with achromatopsia (Kohl 1998). Functional studies indicate this variant may alter protein function (Reuter 2008), though the assay is not clinically validated. In summary, although these data favor pathogenicity of the Gly557Arg variant, additional studies are needed to fully assess its clinical significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.87
D;.;D;.
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.98
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
D;D;.;D
M_CAP
Pathogenic
0.51
D
MetaRNN
Uncertain
0.65
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.7
H;.;H;.
PhyloP100
9.6
PrimateAI
Pathogenic
0.87
D
PROVEAN
Pathogenic
-7.5
D;D;D;D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D
Polyphen
1.0
D;.;D;.
Vest4
0.84
MutPred
0.78
.;.;.;Gain of MoRF binding (P = 0.0268);
MVP
0.99
MPC
0.56
ClinPred
0.94
D
GERP RS
5.4
Varity_R
0.90
gMVP
0.88
Mutation Taster
=0/100
disease causing (ClinVar)

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: rs104893615; hg19: chr2-99013302; API