2-98396039-G-C

Variant names:

• chr2-98396039-G-C
• rs199837807
• NM_001298.3:c.869G>C

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_001298.3(CNGA3):​c.869G>C​(p.Arg290Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R290H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CNGA3 NM_001298.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.60
• Publications: 8 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: G2P, Labcorp Genetics (formerly Invitae), Illumina, PanelApp Australia
• 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 11 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_001298.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-98396039-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 503561.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 105 curated pathogenic missense variants (we use a threshold of 10). The gene has 14 curated benign missense variants. Trascript score misZ: 0.49806 (below the threshold of 3.09). GenCC associations: The gene is linked to achromatopsia 2, CNGA3-related retinopathy, cone-rod dystrophy, achromatopsia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.945

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGA3	NM_001298.3	MANE Select	c.869G>C	p.Arg290Pro	missense	Exon 8 of 8	NP_001289.1
	CNGA3	NM_001079878.2		c.815G>C	p.Arg272Pro	missense	Exon 7 of 7	NP_001073347.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CNGA3	ENST00000272602.7	TSL:1 MANE Select	c.869G>C	p.Arg290Pro	missense	Exon 8 of 8	ENSP00000272602.2
	CNGA3	ENST00000436404.6	TSL:1	c.815G>C	p.Arg272Pro	missense	Exon 7 of 7	ENSP00000410070.2
	CNGA3	ENST00000409937.1	TSL:2	n.1022G>C		non_coding_transcript_exon	Exon 8 of 8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H
PhyloP100		9.6
PrimateAI	Uncertain	0.67	T
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.77		Loss of methylation at R294 (P = 0.0499)
MVP		1.0
MPC		0.61
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.98
gMVP		0.98
Mutation Taster		=8/92	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs199837807; hg19: chr2-99012502;