rs748993388

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_019098.5(CNGB3):​c.446_447insT​(p.Lys149AsnfsTer30) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,962 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. K149K) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CNGB3
NM_019098.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 3.15

Publications

3 publications found
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]
CNGB3 Gene-Disease associations (from GenCC):
  • achromatopsia 3
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia
  • CNGB3-related retinopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • cone dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • achromatopsia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • severe early-childhood-onset retinal dystrophy
    Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 8-86670990-C-CA is Pathogenic according to our data. Variant chr8-86670990-C-CA is described in ClinVar as Pathogenic. ClinVar VariationId is 370100.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
CNGB3NM_019098.5 linkc.446_447insT p.Lys149AsnfsTer30 frameshift_variant Exon 4 of 18 ENST00000320005.6 NP_061971.3
CNGB3XM_011517138.3 linkc.32_33insT p.Lys11AsnfsTer30 frameshift_variant Exon 2 of 16 XP_011515440.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CNGB3ENST00000320005.6 linkc.446_447insT p.Lys149AsnfsTer30 frameshift_variant Exon 4 of 18 1 NM_019098.5 ENSP00000316605.5
CNGB3ENST00000680314.1 linkn.207_208insT non_coding_transcript_exon_variant Exon 2 of 3
CNGB3ENST00000681746.1 linkn.446_447insT non_coding_transcript_exon_variant Exon 4 of 19 ENSP00000505959.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251468
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1460962
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726778
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
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:
86212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5036
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111986
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60302
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Achromatopsia 3 Pathogenic:2
May 22, 2022
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Frameshift: predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic without evidence for the classification (ClinVar ID: VCV000370100). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -

Nov 20, 2015
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

not provided Pathogenic:1
Oct 10, 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.Lys149Asnfs*30) in the CNGB3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CNGB3 are known to be pathogenic (PMID: 28795510). This variant is present in population databases (rs748993388, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with achromatopsia (PMID: 12357335). This variant is also known as c.492_493insT. ClinVar contains an entry for this variant (Variation ID: 370100). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
3.1
Mutation Taster
=3/197
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs748993388; hg19: chr8-87683218; API