chr4-47949866-AG-A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001379270.1(CNGA1):​c.253delC​(p.Leu85PhefsTer4) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000297 in 1,614,024 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

CNGA1
NM_001379270.1 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 2.64

Publications

15 publications found
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]
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 4-47949866-AG-A is Pathogenic according to our data. Variant chr4-47949866-AG-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 225315.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CNGA1NM_001379270.1 linkc.253delC p.Leu85PhefsTer4 frameshift_variant Exon 6 of 11 ENST00000514170.7 NP_001366199.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CNGA1ENST00000514170.7 linkc.253delC p.Leu85PhefsTer4 frameshift_variant Exon 6 of 11 5 NM_001379270.1 ENSP00000426862.3 P29973

Frequencies

GnomAD3 genomes
AF:
0.0000328
AC:
5
AN:
152218
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000962
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000108
AC:
27
AN:
249216
AF XY:
0.0000814
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00145
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.0000294
AC:
43
AN:
1461806
Hom.:
0
Cov.:
30
AF XY:
0.0000289
AC XY:
21
AN XY:
727204
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00103
AC:
41
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111964
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.0000328
AC:
5
AN:
152218
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000962
AC:
5
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000831

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:10
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Retinitis pigmentosa 49 Pathogenic:6
Feb 23, 2023
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 31, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 18, 2016
Soonchunhyang University Bucheon Hospital, Soonchunhyang University Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:reference population

- -

-
Juno Genomics, Hangzhou Juno Genomics, Inc
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PVS1+PM2_Supporting+PM3_Strong+PP1_Strong+PP4 -

Jan 23, 2024
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.010%). Predicted Consequence/Location: Frameshift: predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID: 25268133 /3billion dataset). The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000225315 /PMID: 23462753 /3billion dataset). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Feb 05, 2025
SingHealth Duke-NUS Institute of Precision Medicine
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Null variant is predicted to cause nonsense-mediated decay in a gene where LOF is a known cause of pathogenicity (PVS1). Variant is not found in gnomAD exomes or genomes (PM2) -

not provided Pathogenic:2
Jul 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Leu89Phefs*4) in the CNGA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CNGA1 are known to be pathogenic (PMID: 7479749, 25268133). This variant is present in population databases (rs749012133, gnomAD 0.1%). This premature translational stop signal has been observed in individuals with retinitis pigmentosa (PMID: 23462753, 25268133). It has also been observed to segregate with disease in related individuals. This variant is also known as p.Leu158Phefs*4. ClinVar contains an entry for this variant (Variation ID: 225315). For these reasons, this variant has been classified as Pathogenic. -

Jul 19, 2018
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.265delC variant in the CNGA1 gene has been reported previously in both the homozygous state and the compound heterozygous state with another CNGA1 variant in association with retinitis pigmentosa (Katagiri et al., 2014). This variant causes a frameshift starting with codon Leucine 89, changes this amino acid to a Phenylalanine residue, and creates a premature Stop codon at position 4 of the new reading frame, denoted p.Leu89PhefsX4. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.265delC variant is observed in 26/18870 (0.1378%) alleles from individuals of East Asian background in large population cohorts, with no homozygotes reported (Lek et al., 2016). We interpret c.265delC as a pathogenic variant. -

Retinitis pigmentosa;C3151059:Retinitis pigmentosa 49 Pathogenic:1
Jul 14, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Retinal dystrophy Pathogenic:1
Apr 13, 2017
Blueprint Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
2.6
Mutation Taster
=0/200
disease causing (ClinVar)

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

Publications

Other links and lift over

dbSNP: rs749012133; hg19: chr4-47951883; COSMIC: COSV62057719; API