rs62654397

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM5PP2PP3_StrongPP5_Very_Strong

The NM_000350.3(ABCA4):​c.203C>T​(p.Pro68Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,614,086 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P68R) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 missense

Scores

12
6

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9U:1O:1

Conservation

PhyloP100: 9.79

Publications

11 publications found
Variant links:
Genes affected
ABCA4 (HGNC:34): (ATP binding cassette subfamily A member 4) The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intracellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ABC1 subfamily. Members of the ABC1 subfamily comprise the only major ABC subfamily found exclusively in multicellular eukaryotes. This protein is a retina-specific ABC transporter with N-retinylidene-PE as a substrate. It is expressed exclusively in retina photoreceptor cells, and the gene product mediates transport of an essental molecule, all-trans-retinal aldehyde (atRAL), across the photoreceptor cell membrane. Mutations in this gene are found in patients diagnosed with Stargardt disease, a form of juvenile-onset macular degeneration. Mutations in this gene are also associated with retinitis pigmentosa-19, cone-rod dystrophy type 3, early-onset severe retinal dystrophy, fundus flavimaculatus, and macular degeneration age-related 2. [provided by RefSeq, Sep 2019]
ABCA4 Gene-Disease associations (from GenCC):
  • ABCA4-related retinopathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • cone-rod dystrophy 3
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • severe early-childhood-onset retinal dystrophy
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • retinitis pigmentosa 19
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • cone-rod dystrophy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • retinitis pigmentosa
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Stargardt disease
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 19 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_000350.3
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-94111537-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 99112.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 578 curated pathogenic missense variants (we use a threshold of 10). The gene has 28 curated benign missense variants. Gene score misZ: -0.65813 (below the threshold of 3.09). Trascript score misZ: 1.3628 (below the threshold of 3.09). GenCC associations: The gene is linked to cone-rod dystrophy 3, retinitis pigmentosa 19, ABCA4-related retinopathy, severe early-childhood-onset retinal dystrophy, cone-rod dystrophy, Stargardt disease, retinitis pigmentosa.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.985
PP5
Variant 1-94111537-G-A is Pathogenic according to our data. Variant chr1-94111537-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 99113.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
ABCA4NM_000350.3 linkc.203C>T p.Pro68Leu missense_variant Exon 3 of 50 ENST00000370225.4 NP_000341.2
ABCA4NM_001425324.1 linkc.203C>T p.Pro68Leu missense_variant Exon 3 of 49 NP_001412253.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABCA4ENST00000370225.4 linkc.203C>T p.Pro68Leu missense_variant Exon 3 of 50 1 NM_000350.3 ENSP00000359245.3
ABCA4ENST00000649773.1 linkc.203C>T p.Pro68Leu missense_variant Exon 3 of 19 ENSP00000496882.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152234
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251400
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461852
Hom.:
0
Cov.:
34
AF XY:
0.00000413
AC XY:
3
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111978
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.00000657
AC:
1
AN:
152234
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74388
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 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: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:9Uncertain:1Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 Pathogenic:2
Juno Genomics, Hangzhou Juno Genomics, Inc
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Absent from controls (or at extremely low frequency if recessive) in Genome Aggregation Database, Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium.;Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc).;For recessive disorders, detected in trans with a pathogenic variant.;Patient's phenotype or family history is highly specific for a disease with a single genetic etiology.;Co-segregation with disease in multiple affected family members in a gene definitively known to cause the disease.

May 01, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Retinal dystrophy Pathogenic:2
Jan 01, 2021
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Dec 11, 2017
Blueprint Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Pathogenic:1Other:1
Apr 17, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 68 of the ABCA4 protein (p.Pro68Leu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with ABCA4-related conditions (PMID: 10958763, 19265867, 27939946). ClinVar contains an entry for this variant (Variation ID: 99113). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ABCA4 protein function with a positive predictive value of 95%. This variant disrupts the p.Pro68 amino acid residue in ABCA4. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11726554, 22247458, 28118664). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.

Retina International
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

Age related macular degeneration 2 Pathogenic:1
Jan 01, 2016
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PM3,PP3,PP4,PP5.

ABCA4-related disorder Pathogenic:1
Aug 14, 2023
PreventionGenetics, part of Exact Sciences
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The ABCA4 c.203C>T variant is predicted to result in the amino acid substitution p.Pro68Leu. This variant has been reported in the compound heterozygous state in individuals with Stargardt disease (Rivera et al. 2000. PubMed ID: 10958763; Bertelsen et al. 2014. PubMed ID: 24713488; Family #1034 in Liu et al. 2020. PubMed ID: 32845068; Zhu et al. 2021. PubMed ID: 33732702). This variant is reported in 0.0040% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/1-94577093-G-A). This variant has been classified as pathogenic and likely pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/99113/). Given the evidence, we interpret c.203C>T (p.Pro68Leu) as likely pathogenic.

Abnormal retinal morphology Pathogenic:1
Jan 01, 2017
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Retinitis pigmentosa Pathogenic:1
Apr 30, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ABCA4 c.203C>T (p.Pro68Leu) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251400 control chromosomes. c.203C>T has been reported in the literature in multiple compound heterozygous individuals affected with Stargardt disease, choriocapillaris dystrophy, or other inherited retinal degeneration disorder (e.g. Reinhard_2007, Rivera_2000, Bertelsen_2014, Gatticchi_2021, Zhu_2021). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 24713488, 33724725, 17562343, 10958763, 33732702). ClinVar contains an entry for this variant (Variation ID: 99113). Based on the evidence outlined above, the variant was classified as pathogenic.

Peripheral neuropathy;C4520679:Abnormal macular morphology Uncertain:1
Nov 28, 2013
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Uncertain significance
Review Status:flagged submission
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.38
BayesDel_addAF
Pathogenic
0.51
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.83
D;.
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.91
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D
M_CAP
Pathogenic
0.71
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
0.92
D
MutationAssessor
Pathogenic
3.0
M;.
PhyloP100
9.8
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-6.7
D;.
REVEL
Pathogenic
0.95
Sift
Uncertain
0.0030
D;.
Sift4G
Uncertain
0.0030
D;.
Vest4
0.91
ClinPred
0.99
D
GERP RS
5.6
Varity_R
0.56
gMVP
0.95
Mutation Taster
=1/99
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs62654397; hg19: chr1-94577093; API