rs121918532

Variant names:

• chr16-57897913-C-A
• rs121918532
• NM_001297.5:c.2978G>T

Your query was ambiguous. Multiple possible variants found:

• chr16-57897913-C-A
• chr16-57897913-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3 PP5

The NM_001297.5(CNGB1):​c.2978G>T​(p.Gly993Val) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G993E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CNGB1 NM_001297.5 missense, splice_region
• Scores: Splicing: ADA: 0.9763
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 5.98
• Publications: 8 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 16-57897913-C-A is Pathogenic according to our data. Variant chr16-57897913-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 8897.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001297.5. 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
	CNGB1	NM_001297.5	MANE Select	c.2978G>T	p.Gly993Val	missense splice_region	Exon 30 of 33	NP_001288.3
	CNGB1	NM_001286130.2		c.2960G>T	p.Gly987Val	missense splice_region	Exon 30 of 33	NP_001273059.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGB1	ENST00000251102.13	TSL:1 MANE Select	c.2978G>T	p.Gly993Val	missense splice_region	Exon 30 of 33	ENSP00000251102.8
	CNGB1	ENST00000564448.5	TSL:1	c.2960G>T	p.Gly987Val	missense splice_region	Exon 30 of 33	ENSP00000454633.1
	CNGB1	ENST00000565942.1	TSL:5	c.23G>T	p.Gly8Val	missense splice_region	Exon 2 of 4	ENSP00000455964.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461838 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727230

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

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: 0.00 AC: 0 AN: 1111964

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Retinitis pigmentosa 45 Pathogenic:1

Apr 01, 2001

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.82	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	5.1	H
PhyloP100		6.0
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-8.4	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.94		Gain of methylation at K992 (P = 0.0649)
MVP		0.85
MPC		0.56
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.99
gMVP		0.73
Mutation Taster		=37/63	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.98
dbscSNV1_RF	Pathogenic	0.88
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: rs121918532; hg19: chr16-57931817;