8-86726611-AG-A

Position:

• chr8-86726611-AG-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The ENST00000320005.6(CNGB3):​c.257del​(p.Pro86LeufsTer39) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,606 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. P86P) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CNGB3 ENST00000320005.6 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 0.443

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]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 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 8-86726611-AG-A is Pathogenic according to our data. Variant chr8-86726611-AG-A is described in ClinVar as [Pathogenic]. Clinvar id is 427647.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr8-86726611-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CNGB3	NM_019098.5	c.257del	p.Pro86LeufsTer39	frameshift_variant	3/18	ENST00000320005.6	NP_061971.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CNGB3	ENST00000320005.6	c.257del	p.Pro86LeufsTer39	frameshift_variant	3/18	1	NM_019098.5	ENSP00000316605	P1
	ENST00000519041.1	n.448+18620del		intron_variant, non_coding_transcript_variant		3
CNGB3	ENST00000519777.1	n.239del		non_coding_transcript_exon_variant	3/4	2
CNGB3	ENST00000681746.1	c.257del	p.Pro86LeufsTer39	frameshift_variant, NMD_transcript_variant	3/19			ENSP00000505959

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461606 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727126

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Achromatopsia 3 Pathogenic:1

Pathogenic, no assertion criteria provided

research

Molecular Genetics Laboratory, Institute for Ophthalmic Research

Mar 27, 2017

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 05, 2021

ClinVar contains an entry for this variant (Variation ID: 427647). This premature translational stop signal has been observed in individual(s) with CNGB3-related conditions (PMID: 28795510). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Pro86Leufs*39) 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). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554618420; hg19: chr8-87738839;