rs104893621
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_001298.3(CNGA3):c.1306C>T(p.Arg436Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000694 in 1,613,912 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. R436Q) has been classified as Likely 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 |
---|---|---|---|---|---|---|---|---|---|---|
CNGA3 | ENST00000272602.7 | c.1306C>T | p.Arg436Trp | missense_variant | Exon 8 of 8 | 1 | NM_001298.3 | ENSP00000272602.2 | ||
CNGA3 | ENST00000436404.6 | c.1252C>T | p.Arg418Trp | missense_variant | Exon 7 of 7 | 1 | ENSP00000410070.2 | |||
CNGA3 | ENST00000409937.1 | n.1459C>T | non_coding_transcript_exon_variant | Exon 8 of 8 | 2 |
Frequencies
GnomAD3 genomes AF: 0.0000658 AC: 10AN: 152026Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000957 AC: 24AN: 250684Hom.: 0 AF XY: 0.000111 AC XY: 15AN XY: 135586
GnomAD4 exome AF: 0.0000698 AC: 102AN: 1461768Hom.: 0 Cov.: 31 AF XY: 0.0000756 AC XY: 55AN XY: 727164
GnomAD4 genome AF: 0.0000657 AC: 10AN: 152144Hom.: 0 Cov.: 32 AF XY: 0.000108 AC XY: 8AN XY: 74378
ClinVar
Submissions by phenotype
Achromatopsia 2 Pathogenic:7
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Variant summary: CNGA3 c.1306C>T (p.Arg436Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 9.6e-05 in 250684 control chromosomes. c.1306C>T has been reported in the literature in multiple individuals affected with Achromatopsia and has been shown to segregate in families (eg. Saqib_2015, Wissinger_2001, etc). These data indicate that the variant is very likely to be associated with disease. Experimental studies have shown the variant to have absent cGMP-activated current upon patch-clamp recordings, suggesting that this mutation causes a loss of function of the channels (Muraki-Oda_2007). Additionally, a mouse model demonstrated the variant to result in a loss of activity and impaired cellular trafficking, as a result of changes to the secondary structure (Matveev_2010). Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
The missense variant p.R436W in CNGA3 (NM_001298.3) has been previously reported in multiple affected individuals (Li S et al,Huang L et al). Functional studies suggest a damaging effect (Muraki-Oda S et al). In silico tools are damaging and the residue is poorly conserved across species. For these reasons, this variant has been classified as Pathogenic. -
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not provided Pathogenic:5
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 436 of the CNGA3 protein (p.Arg436Trp). This variant is present in population databases (rs104893621, gnomAD 0.04%). This missense change has been observed in individuals with retinal dystrophy (PMID: 11536077, 25943428, 26992781). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 9482). 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 with a positive predictive value of 95%. Experimental studies have shown that this missense change affects CNGA3 function (PMID: 17693388). For these reasons, this variant has been classified as Pathogenic. -
CNGA3: PM3:Very Strong, PM1, PM2, PS3:Supporting -
Published functional studies demonstrate a damaging effect with loss of activity and impaired cellular trafficking, as a result of changes to the secondary structure (Muraki-Oda et al., 2007; Matveev et al., 2010); This variant is associated with the following publications: (PMID: 16961972, 32531858, 26992781, 20088482, 11536077, 25943428, 25616768, 21778272, 15712225, 14757870, 17693388, 30804581, 30609409, 30682209, 24903488, 30418171, 31456290, 33083013, 34426522) -
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Achromatopsia Pathogenic:3
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The p.Arg436Trp (NM001298.2 c.1306C>T) variant in CNGA3 has been reported in at least 2 homozygous and 10 compound heterozygous individuals with clinical diagno sis of achromatopsia or cone-rod dystrophy (Li 2014, Wissinger 2001, Johnson 200 4, Goto-Omoto 2006, Saqib 2015, Huang 2016, Nishiguchi 2005, Zelinger 2015, and Genead 2011), and segregated in 3 affected homozygous family members in one fami ly (Saqib 2015). This variant has also been identified in 0.036% (6/16,458) of S outh Asian chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.br oadinstitute.org; dbSNP rs104893621). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessi ve carrier frequency. In summary, this variant meets criteria to be classified a s pathogenic for CNGA3-related achromatopsia/ cone-rod dystrophy in an autosomal recessive manner based upon its biallelic occurrence in affected individuals an d low frequency in control populations. -
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Retinal dystrophy Pathogenic:2
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at