4-660484-GC-G

Variant names:

• chr4-660484-GC-G
• rs730880317
• NM_000283.4:c.1488delC

Variant summary

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

The NM_000283.4(PDE6B):​c.1488delC​(p.Thr497ProfsTer78) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,642 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PDE6B NM_000283.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.57
• Publications: 4 publications found

Genes affected

PDE6B (HGNC:8786): (phosphodiesterase 6B) Photon absorption triggers a signaling cascade in rod photoreceptors that activates cGMP phosphodiesterase (PDE), resulting in the rapid hydrolysis of cGMP, closure of cGMP-gated cation channels, and hyperpolarization of the cell. PDE is a peripheral membrane heterotrimeric enzyme made up of alpha, beta, and gamma subunits. This gene encodes the beta subunit. Mutations in this gene result in retinitis pigmentosa and autosomal dominant congenital stationary night blindness. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2009]

PDE6B Gene-Disease associations (from GenCC):

• retinitis pigmentosa 40

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
• congenital stationary night blindness autosomal dominant 2

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• congenital stationary night blindness

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

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 4-660484-GC-G is Pathogenic according to our data. Variant chr4-660484-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 13105.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000283.4. 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
	PDE6B	NM_000283.4	MANE Select	c.1488delC	p.Thr497ProfsTer78	frameshift	Exon 12 of 22	NP_000274.3
	PDE6B	NM_001440547.1		c.1488delC	p.Thr497ProfsTer78	frameshift	Exon 12 of 22	NP_001427476.1
	PDE6B	NM_001145291.2		c.1488delC	p.Thr497ProfsTer78	frameshift	Exon 12 of 22	NP_001138763.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PDE6B	ENST00000496514.6	TSL:1 MANE Select	c.1488delC	p.Thr497ProfsTer78	frameshift	Exon 12 of 22	ENSP00000420295.1
	PDE6B	ENST00000255622.10	TSL:1	c.1488delC	p.Thr497ProfsTer78	frameshift	Exon 12 of 22	ENSP00000255622.6
	PDE6B	ENST00000429163.6	TSL:2	c.651delC	p.Thr218ProfsTer78	frameshift	Exon 10 of 20	ENSP00000406334.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461642 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727110

African (AFR) AF: 0.00 AC: 0 AN: 33476

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53240

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111962

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Retinitis pigmentosa 40 Pathogenic:2

Jun 01, 1993

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Jun 21, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: 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 to be associated with PDE6B related disorder (ClinVar ID: VCV000013105 /PMID: 8394174). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Retinal dystrophy Pathogenic:1

Oct 01, 2023

Dept Of Ophthalmology, Nagoya University

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.6
Mutation Taster		=2/198	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: rs730880317; hg19: chr4-654273;