Genetic Variant NM_019098.5:c.646C>A (chr8-86667131-G-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_019098.5(CNGB3):c.646C>A(p.Arg216Arg) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000000684 in 1,461,130 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R216R) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CNGB3
NM_019098.5 splice_region, synonymous

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 4.06

Publications

0 publications found

Variant links:

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: G2P, Labcorp Genetics (formerly Invitae)
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)

CNGB3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGB3	NM_019098.5	MANE Select	c.646C>A	p.Arg216Arg	splice_region synonymous	Exon 6 of 18	NP_061971.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGB3	ENST00000320005.6	TSL:1 MANE Select	c.646C>A	p.Arg216Arg	splice_region synonymous	Exon 6 of 18	ENSP00000316605.5	Q9NQW8-1
	CNGB3	ENST00000681746.1		n.646C>A		splice_region non_coding_transcript_exon	Exon 6 of 19	ENSP00000505959.1	A0A5J6DSN8

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461130

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726840

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

33460

American (AMR)

AF:

0.00

AC:

AN:

44664

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26118

East Asian (EAS)

AF:

0.00

AC:

AN:

39692

South Asian (SAS)

AF:

0.00

AC:

AN:

86164

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1111496

Other (OTH)

AF:

0.00

AC:

AN:

60364

⚠️ 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.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.42

CADD

Benign

(source)

DANN

Benign

0.87

PhyloP100

4.1

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.45

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.45

Position offset: 2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over