rs147415641

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 4P and 9B. PM1PP2PP3BP4_StrongBS1_SupportingBS2

The NM_001298.3(CNGA3):​c.682G>A​(p.Glu228Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000724 in 1,614,058 control chromosomes in the GnomAD database, including 14 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00084 ( 2 hom., cov: 32)
Exomes 𝑓: 0.00071 ( 12 hom. )

Consequence

CNGA3
NM_001298.3 missense

Scores

8
8
2

Clinical Significance

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

Conservation

PhyloP100: 9.60
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 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, cone-rod dystrophy, Leber congenital amaurosis 9, CNGA3-related retinopathy, achromatopsia 2.
PP3
Multiple lines of computational evidence support a deleterious effect 6: BayesDel_addAF, BayesDel_noAF, Eigen, phyloP100way_vertebrate, REVEL, REVEL [when max_spliceai, FATHMM_MKL, MetaRNN, MutationTaster was below the threshold]
BP4
Computational evidence support a benign effect (MetaRNN=0.030779868).
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000841 (128/152240) while in subpopulation SAS AF = 0.0127 (61/4822). AF 95% confidence interval is 0.0101. There are 2 homozygotes in GnomAd4. There are 77 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position FAILED quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CNGA3NM_001298.3 linkc.682G>A p.Glu228Lys 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.682G>A p.Glu228Lys missense_variant Exon 8 of 8 1 NM_001298.3 ENSP00000272602.2 Q16281-1
CNGA3ENST00000436404.6 linkc.628G>A p.Glu210Lys missense_variant Exon 7 of 7 1 ENSP00000410070.2 Q16281-2
CNGA3ENST00000409937.1 linkn.835G>A non_coding_transcript_exon_variant Exon 8 of 8 2

Frequencies

GnomAD3 genomes
AF:
0.000841
AC:
128
AN:
152122
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00157
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.0126
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00137
AC:
345
AN:
251304
AF XY:
0.00180
show subpopulations
Gnomad AFR exome
AF:
0.00185
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.000711
AC:
1040
AN:
1461818
Hom.:
12
Cov.:
31
AF XY:
0.000976
AC XY:
710
AN XY:
727216
show subpopulations
Gnomad4 AFR exome
AF:
0.00233
AC:
78
AN:
33480
Gnomad4 AMR exome
AF:
0.0000671
AC:
3
AN:
44724
Gnomad4 ASJ exome
AF:
0.00
AC:
0
AN:
26136
Gnomad4 EAS exome
AF:
0.0000756
AC:
3
AN:
39700
Gnomad4 SAS exome
AF:
0.0101
AC:
871
AN:
86204
Gnomad4 FIN exome
AF:
0.0000374
AC:
2
AN:
53420
Gnomad4 NFE exome
AF:
0.0000252
AC:
28
AN:
1111990
Gnomad4 Remaining exome
AF:
0.000878
AC:
53
AN:
60396
Heterozygous variant carriers
0
61
122
182
243
304
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
100
<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:
0.000841
AC:
128
AN:
152240
Hom.:
2
Cov.:
32
AF XY:
0.00103
AC XY:
77
AN XY:
74442
show subpopulations
Gnomad4 AFR
AF:
0.00157
AC:
0.00156559
AN:
0.00156559
Gnomad4 AMR
AF:
0.00
AC:
0
AN:
0
Gnomad4 ASJ
AF:
0.00
AC:
0
AN:
0
Gnomad4 EAS
AF:
0.00
AC:
0
AN:
0
Gnomad4 SAS
AF:
0.0127
AC:
0.0126504
AN:
0.0126504
Gnomad4 FIN
AF:
0.00
AC:
0
AN:
0
Gnomad4 NFE
AF:
0.0000294
AC:
0.0000294031
AN:
0.0000294031
Gnomad4 OTH
AF:
0.00
AC:
0
AN:
0
Heterozygous variant carriers
0
8
16
24
32
40
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Genome Het
Genome Hom
Variant carriers
0
10
20
30
40
50
<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:
0.000285
Hom.:
0
Bravo
AF:
0.000638
ESP6500AA
AF:
0.00113
AC:
5
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00155
AC:
188
Asia WGS
AF:
0.00318
AC:
11
AN:
3478
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

Achromatopsia Pathogenic:2
Jun 23, 2019
Sharon lab, Hadassah-Hebrew University Medical Center
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Mar 20, 2018
Molecular Genetics Laboratory, Institute for Ophthalmic Research
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

Achromatopsia 2 Uncertain:2
-
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

The homozygous p.Glu228Lys variant in CNGA3 has been identified in 2 siblings from 1 family with incomplete achromatopsia and in the heterozygous state in an individual with a different eye phenotype and other missense variants (PMID: 18521937, 20079539), and has been identified in >1% of South Asian chromosomes and a homozygote by ExAC (http://gnomad.broadinstitute.org/). Please note that for diseases with clinical variability, or reduced penetrance, pathogenic variants may be present at a low frequency in the general population. In vitro functional studies provide some evidence that the p.Glu228Lys variant may slightly impact protein function (PMID: 18521937). However, these types of assays may not accurately represent biological function. In summary, the clinical significance of this variant is uncertain. -

Oct 13, 2021
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

not specified Uncertain:1Benign:1
Jun 27, 2018
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 07, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CNGA3 c.682G>A (p.Glu228Lys) results in a conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0014 in 251304 control chromosomes in the gnomAD database, including 2 homozygotes. c.682G>A was found in homozygous state in two siblings with incomplete Achromatopsia (Reuter_ 2008), and in individuals affected with cone dystrophy (Thiadens _2010 and Hitti-malin_CNGA3_HM_2022). In at-least, one of these individuals affected with cone dystrophy authors reported a homozygous variant in CNGB3 (Thiadens _2010). These report(s) do not provide unequivocal conclusions about association of the variant with Achromatopsia 2. At least one publication reports experimental evidence evaluating an impact on protein function. However, it does not provide strong conclusions about the variant association with the disease (Reuter_ 2008). The following publications have been ascertained in the context of this evaluation (PMID: 22995991, 30418171, 36259723, 27535533, 18521937, 26036949, 31456290, 32913385, 20079539). Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as benign/likely benign (n=2), pathogenic/likely pathogenic (n=2) and as uncertain significance (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Retinal dystrophy Pathogenic:1
Jan 01, 2022
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Dec 04, 2024
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
AlphaMissense
Uncertain
0.36
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.53
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.85
D;.;D;.
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.70
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
D;D;.;D
MetaRNN
Benign
0.031
T;T;T;T
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.7
M;.;M;.
PrimateAI
Uncertain
0.66
T
PROVEAN
Uncertain
-3.7
D;D;D;D
REVEL
Pathogenic
0.91
Sift
Uncertain
0.0010
D;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D
Polyphen
0.96
D;.;D;.
Vest4
0.89
MVP
0.99
MPC
0.42
ClinPred
0.057
T
GERP RS
5.3
Varity_R
0.90
gMVP
0.78
Mutation Taster
=24/76
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

LitVar

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

Other links and lift over

dbSNP: rs147415641; hg19: chr2-99012315; COSMIC: COSV55623781; API