4-47937535-G-C

Position:

chr4-47937535-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_001379270.1(CNGA1):c.947C>G(p.Ser316Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000805 in 1,614,062 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S316F) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

CNGA1
NM_001379270.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.54

Variant links:

Genes affected

CNGA1 (HGNC:2148): (cyclic nucleotide gated channel subunit alpha 1) The protein encoded by this gene is involved in phototransduction. Along with another protein, the encoded protein forms a cGMP-gated cation channel in the plasma membrane, allowing depolarization of rod photoreceptors. This represents the last step in the phototransduction pathway. Defects in this gene are a cause of retinitis pigmentosa autosomal recessive (ARRP) disease. Multiple transcript variants have been found for this gene. [provided by RefSeq, Oct 2019]

CNGA1 links:

NIPAL1 (HGNC:27194): (NIPA like domain containing 1) Predicted to enable magnesium ion transmembrane transporter activity. Predicted to be involved in magnesium ion transport. Predicted to be integral component of membrane. Predicted to be active in membrane. [provided by Alliance of Genome Resources, Apr 2022]

NIPAL1 links:

LOC101927157 (HGNC:):

LOC101927157 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr4-47937535-G-A is described in Lovd as [Likely_pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.867

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CNGA1	NM_001379270.1 link	c.947C>G	p.Ser316Cys	missense_variant	11/11	ENST00000514170.7	NP_001366199.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CNGA1	ENST00000514170.7 link	c.947C>G	p.Ser316Cys	missense_variant	11/11	5	NM_001379270.1	ENSP00000426862.3		P29973

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000241

AC:

AN:

249220

Hom.:

AF XY:

0.0000370

AC XY:

AN XY:

135210

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000531

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000752

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000989

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000478

Bravo

AF:

0.00000378

ExAC

AF:

0.0000248

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jul 18, 2024

Variant summary: CNGA1 c.947C>G (p.Ser316Cys) results in a non-conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 249220 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.947C>G in individuals affected with Retinitis Pigmentosa and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 967684). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 22, 2022

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 320 of the CNGA1 protein (p.Ser320Cys). This variant is present in population databases (rs62625014, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with CNGA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 967684). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant disrupts the p.Ser320 amino acid residue in CNGA1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7479749, 24265693, 25326637). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.31

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.67

.;D;.;D;D

Eigen

Pathogenic

0.76

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.93

.;.;D;D;.

M_CAP

Uncertain

0.25

MetaRNN

Pathogenic

0.87

D;D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.4

.;M;.;M;M

PrimateAI

Uncertain

0.65

PROVEAN

Benign

-2.3

N;N;.;N;N

REVEL

Pathogenic

0.85

Sift

Uncertain

0.011

D;D;.;D;D

Sift4G

Uncertain

0.0090

D;D;D;D;D

Polyphen

1.0

.;D;.;D;D

Vest4

0.79

MutPred

0.68

.;Loss of glycosylation at S322 (P = 0.017);.;Loss of glycosylation at S322 (P = 0.017);Loss of glycosylation at S322 (P = 0.017);

MVP

1.0

MPC

0.52

ClinPred

0.63

GERP RS

4.8

Varity_R

0.64

gMVP

0.76

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over