16-57882558-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001297.5(CNGB1):c.*1606G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00147 in 152,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0015 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CNGB1 NM_001297.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.209

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CNGB1	NM_001297.5	c.*1606G>A		3_prime_UTR_variant	33/33	ENST00000251102.13
CNGB1	NM_001286130.2	c.*1606G>A		3_prime_UTR_variant	33/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CNGB1	ENST00000251102.13	c.*1606G>A		3_prime_UTR_variant	33/33	1	NM_001297.5	P4

Frequencies

GnomAD3 genomes AF: 0.00148 AC: 225 AN: 152022 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000363

Gnomad AMI AF: 0.00219

Gnomad AMR AF: 0.000525

Gnomad ASJ AF: 0.000865

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00477

Gnomad FIN AF: 0.000472

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00244

Gnomad OTH AF: 0.000956

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 2 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

Gnomad4 NFE exome AF: 0.00

GnomAD4 genome AF: 0.00147 AC: 224 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.00152 AC XY: 113 AN XY: 74390

Gnomad4 AFR AF: 0.000362

Gnomad4 AMR AF: 0.000524

Gnomad4 ASJ AF: 0.000865

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00456

Gnomad4 FIN AF: 0.000472

Gnomad4 NFE AF: 0.00244

Gnomad4 OTH AF: 0.000946

Alfa AF: 0.00212 Hom.: 0

Bravo AF: 0.00128

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Retinitis pigmentosa Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
Cadd	Benign	4.7
Dann	Benign	0.50

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: rs185229037; hg19: chr16-57916462;