Table 2. Disease-Causing Variants in CNGB1 and Classification in This Study.
Variant on Nucleotide Level | Consequence/Variant on Protein Level | Location in CNGB1 Polypeptide | gnomAD Browser MAF, %a | Conservation Among Different Speciesb | Predictionc | ACMG Scoring | Source |
---|---|---|---|---|---|---|---|
c.413-1G>A | Splice defect | N-terminal GARP | 0.008 | NA | Human Splice Finder and MaxEntScan: broken wild-type acceptor site, new acceptor site | Pathogenic (Class Ic) | Azam et al,15 2011 |
c.1312C>T | p.Q438* | N-terminal GARP | NA | NA | Mutationtaster: disease causing | Pathogenic (Class Ib) | Present study |
c.2210G>A | p.R737H | TD3 | 0.002 | HsCNGB1 R, MmCNGB1 R, DrCngb1 R | PolyPhen-2: probably damaging (score 0.999), SIFT: damaging (score 0.4), Mutationtaster: disease causing | VUS | Present study |
c.2284C>T | p.R762C | TD4 | 0.001 | HsCNGB1 R, MmCNGB1 R, DrCngb1 R | PolyPhen-2: probably damaging (score 1.000), SIFT: damaging (score 0), Mutationtaster: disease causing | VUS | Azam et al,15 2011 |
c.2492+1G>A | Splice defect | Pore | NA | NA | Human Splice Finder and MaxEntScan: broken wild-type donor site | Pathogenic (Class Ib) | Present study |
c.2542_2543insA | p.G848Efs*4 | Linker pore–TD6 | NA | NA | Mutationtaster: disease causing | Pathogenic (Class Ib) | Oishi et al,22 2014 |
c.2763C>G | p.Y921* | C-linker | NA | NA | Mutationtaster: disease causing | Pathogenic (Class Ib) | Present study |
c.2957A>T | p.N986I | CNBD | 0.123 | HsCNGB1 N, MmCNGB1 N, DrCngb1 G | PolyPhen-2: probably damaging (score 0.983), SIFT: damaging (score 0), Mutationtaster: disease causing | VUS | Simpson et al,16 2011 |
c.3044_3050delGGAAATC | p.G1015Vfs*4 | CNBD | NA | NA | Mutation taster: disease causing | Pathogenic (Class Ib) | Present study |
c.3139_3142dupGTGG | p.A1048Gfs*13 | CNBD | NA | NA | Mutation taster: disease causing | Pathogenic (Class Ib) | Hull et al,27 2017 |
Abbreviations: ACMG, American College of Medical Genetics and Genomics; CNBD, cyclic nucleotide–binding domain; Dr, Danio rerio; GARP, glutamic acid–rich protein; Hs, Homo sapiens; MAF, minor allele frequency; Mm, Mus musculus; TD, transmembrane domain; NA, not applicable; VUS, variant of uncertain significance.
gnomAD (http://gnomad.broadinstitute.org/).
Amino acid residue affected by mutation is given in 1-letter code.
PolyPhen-2 (http://genetics.bwh.harvard.edu/pph2/), SIFT (http://sift.jcvi.org/), and Mutationtaster (http://www.mutationtaster.org/) for prediction for missense variants and Human Splice Finder (http://www.umd.be/HSF3/) and MaxEntScan (http://genes.mit.edu/burgelab/maxent/Xmaxentscan_scoreseq.html) for prediction of splice-site variants.