8-86579218-CA-C

Variant names:

• chr8-86579218-CA-C
• rs1362472371
• NM_019098.5:c.1815delT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_019098.5(CNGB3):​c.1815delT​(p.Ala606ProfsTer12) 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 1,461,834 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. T605T) 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
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -1.71
• Publications: 0 publications found

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)

ACMG classification

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 8-86579218-CA-C is Pathogenic according to our data. Variant chr8-86579218-CA-C is described in ClinVar as Pathogenic. ClinVar VariationId is 427666.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_019098.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGB3	NM_019098.5	MANE Select	c.1815delT	p.Ala606ProfsTer12	frameshift	Exon 16 of 18	NP_061971.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGB3	ENST00000320005.6	TSL:1 MANE Select	c.1815delT	p.Ala606ProfsTer12	frameshift	Exon 16 of 18	ENSP00000316605.5
	CNGB3	ENST00000681546.1		n.1635delT		non_coding_transcript_exon	Exon 11 of 13
	CNGB3	ENST00000681746.1		n.*226delT		non_coding_transcript_exon	Exon 17 of 19	ENSP00000505959.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251110 AF XY: 0.00

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461834 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727218

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

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: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111972

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Nov 06, 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; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 31964843, 28795510)

May 12, 2021

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.Ala606Profs*12) 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 not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with achromatopsia (PMID: 28795510). ClinVar contains an entry for this variant (Variation ID: 427666). For these reasons, this variant has been classified as Pathogenic.

Achromatopsia 3 Pathogenic:1

Mar 27, 2017

Molecular Genetics Laboratory, Institute for Ophthalmic Research

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-1.7
Mutation Taster		=5/195	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1362472371; hg19: chr8-87591446;