rs1026427970

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PM2PP5_Very_StrongBP4

The NM_019098.5(CNGB3):​c.1320+4A>G variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,612,976 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

CNGB3
NM_019098.5 splice_donor_region, intron

Scores

2
Splicing: ADA: 0.4503
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2U:1

Conservation

PhyloP100: 2.70
Variant links:
Genes affected
CNGB3 (HGNC:2153): (cyclic nucleotide gated channel subunit beta 3) This gene encodes the beta subunit of a cyclic nucleotide-gated ion channel. The encoded beta subunit appears to play a role in modulation of channel function in cone photoreceptors. This heterotetrameric channel is necessary for sensory transduction, and mutations in this gene have been associated with achromatopsia 3, progressive cone dystrophy, and juvenile macular degeneration, also known as Stargardt Disease. [provided by RefSeq, Feb 2010]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-86632748-T-C is Pathogenic according to our data. Variant chr8-86632748-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 427703.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr8-86632748-T-C is described in Lovd as [Pathogenic].
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.36). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
CNGB3NM_019098.5 linkuse as main transcriptc.1320+4A>G splice_donor_region_variant, intron_variant ENST00000320005.6
CNGB3XM_011517138.3 linkuse as main transcriptc.906+4A>G splice_donor_region_variant, intron_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
CNGB3ENST00000320005.6 linkuse as main transcriptc.1320+4A>G splice_donor_region_variant, intron_variant 1 NM_019098.5 P1Q9NQW8-1
CNGB3ENST00000681746.1 linkuse as main transcriptc.1320+4A>G splice_donor_region_variant, intron_variant, NMD_transcript_variant
CNGB3ENST00000681546.1 linkuse as main transcriptn.1140+4A>G splice_donor_region_variant, intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152170
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1460806
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
726730
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152170
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74338
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000659
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Achromatopsia 3 Pathogenic:1Uncertain:1
Uncertain significance, no assertion criteria providedresearchMolecular Genetics Laboratory, Institute for Ophthalmic ResearchMar 27, 2017- -
Likely pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJul 27, 2023Variant summary: CNGB3 c.1320+4A>G alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 3/4 computational tools predict no significant impact on normal splicing, while 1 tool predicts that it weakens the canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 250378 control chromosomes (gnomAD). c.1320+4A>G has been reported in the literature in individuals affected with Achromatopsia (Langlo_2016, Mayer_2017, Ganapathi_2022), and some were reported as compound heterozygous with other (likely) pathogenic variants. These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 27479814, 28795510, 35672425). Two submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. One submitter classified the variant as pathogenic, and one classified it as uncertain significance. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
not provided Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpSep 26, 2023This sequence change falls in intron 11 of the CNGB3 gene. It does not directly change the encoded amino acid sequence of the CNGB3 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has been observed in individual(s) with achromatopsia (PMID: 27479814, 28795510; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 427703). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.36
CADD
Benign
10
DANN
Benign
0.92

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.45
dbscSNV1_RF
Benign
0.42
SpliceAI score (max)
0.69
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.69
Position offset: 4

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: rs1026427970; hg19: chr8-87644976; API