rs886044756

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate

The NM_000350.3(ABCA4):​c.5909T>G​(p.Leu1970Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging 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. L1970F) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 missense

Scores

17
1
1

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 9.26
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM1
In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000350.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-94007731-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1392712.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.958
PP5
Variant 1-94007730-A-C is Pathogenic according to our data. Variant chr1-94007730-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3672358.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ABCA4NM_000350.3 linkc.5909T>G p.Leu1970Arg missense_variant Exon 43 of 50 ENST00000370225.4 NP_000341.2 P78363Q6AI28
ABCA4NM_001425324.1 linkc.5687T>G p.Leu1896Arg missense_variant Exon 42 of 49 NP_001412253.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ABCA4ENST00000370225.4 linkc.5909T>G p.Leu1970Arg missense_variant Exon 43 of 50 1 NM_000350.3 ENSP00000359245.3 P78363
ABCA4ENST00000465352.1 linkn.325T>G non_coding_transcript_exon_variant Exon 4 of 6 5
ABCA4ENST00000484388.1 linkn.23T>G non_coding_transcript_exon_variant Exon 1 of 2 2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000399
AC:
1
AN:
250648
Hom.:
0
AF XY:
0.00000737
AC XY:
1
AN XY:
135622
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:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461732
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727152
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:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74354
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Aug 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1970 of the ABCA4 protein (p.Leu1970Arg). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This missense change has been observed in individual(s) with cone-rod dystrophy and/or Stargardt disease (PMID: 36672815; Invitae). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ABCA4 protein function with a positive predictive value of 95%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.91
D;D
Eigen
Pathogenic
0.99
Eigen_PC
Pathogenic
0.89
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.45
D
MetaRNN
Pathogenic
0.96
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.2
.;H
PrimateAI
Pathogenic
0.85
D
PROVEAN
Pathogenic
-5.6
.;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
.;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.99
MutPred
0.81
.;Gain of methylation at L1970 (P = 0.0048);
MVP
0.98
MPC
0.56
ClinPred
1.0
D
GERP RS
5.1
Varity_R
0.99
gMVP
0.99

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.

Other links and lift over

dbSNP: rs886044756; hg19: chr1-94473286; API