rs753625117

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PP2PP3_StrongPP5_Very_Strong

The NM_001298.3(CNGA3):​c.955T>C​(p.Cys319Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,614,130 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000082 ( 1 hom. )

Consequence

CNGA3
NM_001298.3 missense

Scores

15
2
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.67

Publications

5 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 15 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, 5 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.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.982
PP5
Variant 2-98396125-T-C is Pathogenic according to our data. Variant chr2-98396125-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 191120.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.955T>C p.Cys319Arg 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.955T>C p.Cys319Arg missense_variant Exon 8 of 8 1 NM_001298.3 ENSP00000272602.2 Q16281-1
CNGA3ENST00000436404.6 linkc.901T>C p.Cys301Arg missense_variant Exon 7 of 7 1 ENSP00000410070.2 Q16281-2
CNGA3ENST00000409937.1 linkn.1108T>C non_coding_transcript_exon_variant Exon 8 of 8 2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152236
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000159
AC:
4
AN:
251480
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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:
0.00000821
AC:
12
AN:
1461894
Hom.:
1
Cov.:
31
AF XY:
0.0000110
AC XY:
8
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000139
AC:
12
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.00000657
AC:
1
AN:
152236
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74366
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41474
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
-
Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

- -

May 15, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects CNGA3 function (PMID: 25052312). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CNGA3 protein function. ClinVar contains an entry for this variant (Variation ID: 191120). This missense change has been observed in individuals with inherited retinal disease (PMID: 25052312, 26355662). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs753625117, gnomAD 0.01%). This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 319 of the CNGA3 protein (p.Cys319Arg). -

Achromatopsia 2 Pathogenic:1
-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missense variant p.C319R in CNGA3 (NM_001298.3) has been observed previously in homozygous state in affected individuals (Shaikh RS et al, Patel N et al). The variant has been submitted to ClinVar as Pathogenic/Likely Pathogenic. The p.C319R variant is observed in 4/30,616 (0.0131%) alleles from individuals of South Asian background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. The p.C319R missense variant is predicted to be damaging by both SIFT and PolyPhen2. The cysteine residue at codon 319 of CNGA3 is conserved in all mammalian species. The nucleotide c.955 in CNGA3 is predicted conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.96
D;.;D;.
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.84
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.73
T;T;.;T
M_CAP
Pathogenic
0.75
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.3
H;.;H;.
PhyloP100
7.7
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-12
D;D;D;D
REVEL
Pathogenic
0.99
Sift
Uncertain
0.0010
D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D
Polyphen
1.0
D;.;D;.
Vest4
0.93
MutPred
0.81
.;.;.;Gain of MoRF binding (P = 0.0115);
MVP
1.0
MPC
0.68
ClinPred
1.0
D
GERP RS
5.0
Varity_R
0.98
gMVP
1.0
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: rs753625117; hg19: chr2-99012588; API