2-98395852-G-T

Variant names:

• chr2-98395852-G-T
• rs147415641
• NM_001298.3:c.682G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_001298.3(CNGA3):​c.682G>T​(p.Glu228*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,816 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CNGA3 NM_001298.3 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.60
• Publications: 0 publications found

Genes affected

CNGA3 (HGNC:2150): (cyclic nucleotide gated channel subunit alpha 3) This gene encodes a member of the cyclic nucleotide-gated cation channel protein family which is required for normal vision and olfactory signal transduction. Mutations in this gene are associated with achromatopsia (rod monochromacy) and color blindness. Two alternatively spliced transcripts encoding different isoforms have been described. [provided by RefSeq, Jul 2008]

CNGA3 Gene-Disease associations (from GenCC):

• achromatopsia 2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Illumina, G2P, Labcorp Genetics (formerly Invitae)
• CNGA3-related retinopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• cone-rod dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• achromatopsia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 173 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001298.3. 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
	CNGA3	NM_001298.3	MANE Select	c.682G>T	p.Glu228*	stop_gained	Exon 8 of 8	NP_001289.1	Q16281-1
	CNGA3	NM_001079878.2		c.628G>T	p.Glu210*	stop_gained	Exon 7 of 7	NP_001073347.1	Q16281-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGA3	ENST00000272602.7	TSL:1 MANE Select	c.682G>T	p.Glu228*	stop_gained	Exon 8 of 8	ENSP00000272602.2	Q16281-1
	CNGA3	ENST00000436404.6	TSL:1	c.628G>T	p.Glu210*	stop_gained	Exon 7 of 7	ENSP00000410070.2	Q16281-2
	CNGA3	ENST00000853268.1		c.847G>T	p.Glu283*	stop_gained	Exon 9 of 9	ENSP00000523327.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461816 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727214

⚠️ 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: 33480

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: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86202

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: 1111990

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ 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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.6
Vest4		0.89
GERP RS		5.3
Mutation Taster		=3/197	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs147415641; hg19: chr2-99012315; COSMIC: COSV55628913;