rs104893614
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_001298.3(CNGA3):c.848G>A(p.Arg283Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000062 in 1,614,160 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R283W) has been classified as Pathogenic.
Frequency
Consequence
NM_001298.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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CNGA3 | ENST00000272602.7 | c.848G>A | p.Arg283Gln | missense_variant | Exon 8 of 8 | 1 | NM_001298.3 | ENSP00000272602.2 | ||
CNGA3 | ENST00000436404.6 | c.794G>A | p.Arg265Gln | missense_variant | Exon 7 of 7 | 1 | ENSP00000410070.2 | |||
CNGA3 | ENST00000409937.1 | n.1001G>A | non_coding_transcript_exon_variant | Exon 8 of 8 | 2 |
Frequencies
GnomAD3 genomes AF: 0.0000920 AC: 14AN: 152166Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000637 AC: 16AN: 251352Hom.: 0 AF XY: 0.0000736 AC XY: 10AN XY: 135868
GnomAD4 exome AF: 0.0000588 AC: 86AN: 1461876Hom.: 0 Cov.: 31 AF XY: 0.0000619 AC XY: 45AN XY: 727234
GnomAD4 genome AF: 0.0000919 AC: 14AN: 152284Hom.: 0 Cov.: 32 AF XY: 0.0000806 AC XY: 6AN XY: 74472
ClinVar
Submissions by phenotype
Achromatopsia 2 Pathogenic:4
Variant summary: CNGA3 c.848G>A (p.Arg283Gln) results in a conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6.4e-05 in 251352 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in CNGA3 causing Achromatopsia 2, allowing no conclusion about variant significance. c.848G>A has been reported in the literature in multiple compound heterozygous and homozygous individuals affected with Achromatopsia 2 (e.g. Reuter_2008, Weisschuh_2020). These data indicate that the variant is very likely to be associated with disease. Publication also reported experimental evidence evaluating an impact on protein function, and demonstrated detrimental effect for the variant (e.g. Reuter_2008, Muraki-Oda_2007). The following publications have been ascertained in the context of this evaluation (PMID: 18521937, 32531858, 17693388). ClinVar contains an entry for this variant (Variation ID: 9475). Based on the evidence outlined above, the variant was classified as pathogenic. -
Across a selection of the available literature, the CNGA3 c.848G>A (p.Arg283Gln) variant has been reported in at least four studies and is found in twelve affected individuals including eleven in a compound heterozygous state and one in a heterozygous state with an undetected second allele (Wissinger et al. 2001; Reuter et al. 2008; Genead et al. 2011; Sundaram et al. 2014). Control data are unavailable for this variant, which is reported at a frequency of 0.000063 in the European (non-Finnish) population of the Genome Aggregation Database. Analysis in HEK293 cells found the p.Arg282Gln was associated with deficient trafficking and co-localization with plasma membranes (Reuter et al. 2008). Based on the evidence, the p.Arg283Gln variant is classified as pathogenic for achromatopsia. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
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not provided Pathogenic:3
Published functional studies demonstrate a damaging effect (Muraki-Oda et al., 2007; Reuter et al., 2008); 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: 21912902, 18445228, 25616768, 11536077, 23362848, 21778272, 31144483, 30682209, 31456290, 17693388, 9662398, 24148654, 32531858, 18521937) -
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This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 283 of the CNGA3 protein (p.Arg283Gln). This variant is present in population databases (rs104893614, gnomAD 0.01%). This missense change has been observed in individuals with achromatopsia (PMID: 9662398, 18445228, 24148654). ClinVar contains an entry for this variant (Variation ID: 9475). 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 have shown that this missense change affects CNGA3 function (PMID: 17693388). This variant disrupts the p.Arg283 amino acid residue in CNGA3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9662398, 11536077, 17693388, 20238023, 25637600). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Retinal dystrophy Pathogenic:2
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Achromatopsia Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at