rs62645944

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PP3_StrongPP5_Very_Strong

The NM_000350.3(ABCA4):​c.768G>T​(p.Val256Val) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.0000793 in 1,614,042 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000081 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 splice_region, synonymous

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:20O:1

Conservation

PhyloP100: 5.74

Publications

57 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 12 ACMG points.

PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 1-94098794-C-A is Pathogenic according to our data. Variant chr1-94098794-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 99505.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.768G>T p.Val256Val splice_region_variant, synonymous_variant Exon 6 of 50 ENST00000370225.4 NP_000341.2 P78363Q6AI28
ABCA4NM_001425324.1 linkc.768G>T p.Val256Val splice_region_variant, synonymous_variant Exon 6 of 49 NP_001412253.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABCA4ENST00000370225.4 linkc.768G>T p.Val256Val splice_region_variant, synonymous_variant Exon 6 of 50 1 NM_000350.3 ENSP00000359245.3 P78363
ABCA4ENST00000649773.1 linkc.768G>T p.Val256Val splice_region_variant, synonymous_variant Exon 6 of 19 ENSP00000496882.1 A0A3B3IRV8

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152216
Hom.:
0
Cov.:
33
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000875
AC:
22
AN:
251394
AF XY:
0.0000589
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000193
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000814
AC:
119
AN:
1461826
Hom.:
0
Cov.:
31
AF XY:
0.0000756
AC XY:
55
AN XY:
727212
show subpopulations
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:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53370
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000103
AC:
115
AN:
1112000
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
8
16
25
33
41
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000591
AC:
9
AN:
152216
Hom.:
0
Cov.:
33
AF XY:
0.0000672
AC XY:
5
AN XY:
74366
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15286
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:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000132
AC:
9
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000725
Hom.:
0
Bravo
AF:
0.0000491
EpiCase
AF:
0.000164
EpiControl
AF:
0.000178

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:20Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:8Other:1
Jun 14, 2022
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

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

- -

Mar 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ABCA4: PM3:Very Strong, PM2, PP3, PS3:Supporting -

Dec 29, 2022
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate a damaging effect, specifically, the c.768 G>T variant results in low or absent mRNA expression (Maugeri et al., 1999); In silico analysis is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 26261413, 15161829, 23695285, 28118664, 31429209, 32531858, 31522899, 33706644, 22968130, 19074458, 24453473, 22264887, 10090887, 23891399, 28771251, 29310964, 31618761, 30903310, 32581362, 32810830, 33851411, 31573552, 31589614, 29555955, 30718709, 29162642, 20647261, 35119454, 35112029, 22328824, 29925512) -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sep 15, 2021
Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 16, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects codon 256 of the ABCA4 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the ABCA4 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (rs62645944, gnomAD 0.02%). This variant has been observed in individual(s) with Stargardt disease (PMID: 10090887, 11726554, 15161829, 23695285). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 99505). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in activation of a cryptic splice site, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 10090887, 29162642). For these reasons, this variant has been classified as Pathogenic. -

Dec 09, 2016
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Severe early-childhood-onset retinal dystrophy Pathogenic:3
Jan 01, 2016
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 2015
NIHR Bioresource Rare Diseases, University of Cambridge
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Jan 30, 2021
Institute of Medical Molecular Genetics, University of Zurich
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Retinal dystrophy Pathogenic:2
Jan 01, 2023
Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 06, 2019
Blueprint Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

ABCA4-related disorder Pathogenic:1
Aug 11, 2023
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The ABCA4 c.768G>T variant is not predicted to result in an amino acid change (p.=). However, this variant is predicted to impact splicing (Alamut Visual v.2.11). This variant has been reported many times in the compound heterozygous state to be causative for severe autosomal recessive retinal disorders (see for examples Maugeri et al. 1999. PubMed ID: 10090887; Table S2 in Schulz et al. 2017. PubMed ID: 28118664; Table S1 in Birtel et al. 2018. PubMed ID: 29555955; Table S4 in Jespersgaard et al. 2019. PubMed ID: 30718709). Functional analysis using RT-PCR confirmed that this variant affects splicing and results in an abnormal splicing product (Sangermano et al. 2018. PubMed ID: 29162642). This variant is reported in 0.019% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/1-94564350-C-A). Given the evidence, we interpret c.768G>T (p.=) as pathogenic. -

Macular dystrophy Pathogenic:1
Apr 01, 2018
Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Retinitis pigmentosa 19 Pathogenic:1
Sep 01, 2016
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Cone-rod dystrophy 3 Pathogenic:1
Mar 28, 2023
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Criteria applied: PS3,PM3_STR,PM2_SUP,PP3 -

Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 Pathogenic:1
May 09, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Retinitis pigmentosa Pathogenic:1
Apr 01, 2018
Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Stargardt disease Pathogenic:1
Mar 30, 2023
Molecular Genetics, Royal Melbourne Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change is a synonymous (silent) variant in exon 6 of ABCA4 that is predicted to impact splicing (SpliceAI, MaxEntScan, NNSplice). This prediction is confirmed by RT-PCR analysis of patient RNA and midi-gene generated from bacterial artificial chromosome. The assays demonstrated that the variant impacts splicing by cryptic donor site activiation in intron 6 producing a 35 bp frame-shift insertion (p.Leu257Valfs*17; PMID: 10090887, 29162642). The highest population minor allele frequency in gnomAD v2.1 is 0.02% (24/129,168 alleles) in the European (non-Finnish) population, which is consistent with recessive disease. This variant has been detected homozygous and compound heterozygous with a second pathogenic variant in multiple invidivuals with various retinal disorders, including retinitis pimentosa, Stargardt disease, and unscpeficied macular dystrophy (PMID: 10090887, 11726554, 28118664, 30718709, 33546218). Based on the classification scheme RMH Modified ACMG Guidelines v1.5.1, this variant is classified as PATHOGENIC. Following criteria are met: PS3, PM3_VeryStrong, PM2_Supporting, PP3. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.24
CADD
Benign
23
DANN
Benign
0.91
PhyloP100
5.7
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
0.71
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.71
Position offset: -35
DS_DL_spliceai
0.42
Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs62645944; hg19: chr1-94564350; API