chr16-57897496-G-GCCAC

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001297.5(CNGB1):​c.3139_3142dupGTGG​(p.Ala1048GlyfsTer13) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000892 in 1,613,922 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A1048A) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000095 ( 0 hom. )

Consequence

CNGB1
NM_001297.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.91

Publications

4 publications found
Variant links:
Genes affected
CNGB1 (HGNC:2151): (cyclic nucleotide gated channel subunit beta 1) In humans, the rod photoreceptor cGMP-gated cation channel helps regulate ion flow into the rod photoreceptor outer segment in response to light-induced alteration of the levels of intracellular cGMP. This channel consists of two subunits, alpha and beta, with the protein encoded by this gene representing the beta subunit. Defects in this gene are a cause of cause of retinitis pigmentosa type 45. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2013]
CNGB1 Gene-Disease associations (from GenCC):
  • CNGB1-related retinopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • retinitis pigmentosa 45
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • retinitis pigmentosa
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 16-57897496-G-GCCAC is Pathogenic according to our data. Variant chr16-57897496-G-GCCAC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 437975.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
CNGB1NM_001297.5 linkc.3139_3142dupGTGG p.Ala1048GlyfsTer13 frameshift_variant Exon 31 of 33 ENST00000251102.13 NP_001288.3 Q14028-1
CNGB1NM_001286130.2 linkc.3121_3124dupGTGG p.Ala1042GlyfsTer13 frameshift_variant Exon 31 of 33 NP_001273059.1 Q14028-4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CNGB1ENST00000251102.13 linkc.3139_3142dupGTGG p.Ala1048GlyfsTer13 frameshift_variant Exon 31 of 33 1 NM_001297.5 ENSP00000251102.8 Q14028-1
CNGB1ENST00000564448.5 linkc.3121_3124dupGTGG p.Ala1042GlyfsTer13 frameshift_variant Exon 31 of 33 1 ENSP00000454633.1 Q14028-4
CNGB1ENST00000565942.1 linkc.184_187dupGTGG p.Ala63fs frameshift_variant Exon 3 of 4 5 ENSP00000455964.1 H3BQW3

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152086
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000361
AC:
9
AN:
249502
AF XY:
0.0000591
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:
0.0000795
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000951
AC:
139
AN:
1461836
Hom.:
0
Cov.:
33
AF XY:
0.000102
AC XY:
74
AN XY:
727226
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
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:
0.000120
AC:
133
AN:
1111962
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
9
18
26
35
44
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000329
AC:
5
AN:
152086
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74292
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41400
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Mar 27, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 34426522, 32531858, 28041643, 34906470, 31980526, 32967234, 28056120, 33847019) -

Nov 05, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Ala1048Glyfs*13) in the CNGB1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CNGB1 are known to be pathogenic (PMID: 15557452, 24043777). This variant is present in population databases (rs756806434, gnomAD 0.008%). This premature translational stop signal has been observed in individual(s) with retinitis pigmentosa (PMID: 28056120). ClinVar contains an entry for this variant (Variation ID: 437975). For these reasons, this variant has been classified as Pathogenic. -

Retinitis pigmentosa Pathogenic:2
Apr 01, 2021
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

The p.Ala1048GlyfsTer13 variant in CNGB1 was identified in an individual with Retinitis pigmentosa, via a collaborative study between the Broad Institute's Center for Mendelian Genomics and the Pierce lab (https://oculargenomics.meei.harvard.edu/labs/pierce-lab/lab-members/). Through a review of available evidence we were able to apply the following criteria: PVS1, PM2. Based on this evidence we have classified this variant as Likely Pathogenic. If you have any questions about the classification please reach out to the Pierce Lab. -

Jan 01, 2015
NIHR Bioresource Rare Diseases, University of Cambridge
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Retinitis pigmentosa 45 Pathogenic:1
Apr 23, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Retinal dystrophy Pathogenic:1
Dec 17, 2018
Blueprint Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
7.9
Mutation Taster
=4/196
disease causing (ClinVar)

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs756806434; hg19: chr16-57931400; API