rs1553192682

chr1-94063115-T-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_000350.3(ABCA4):c.1757A>G(p.Asp586Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. D586E) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ABCA4 NM_000350.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.02

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 3 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 chr1-94063114-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1024921.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.888
• PP5: Variant 1-94063115-T-C is Pathogenic according to our data. Variant chr1-94063115-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 438089.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-94063115-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCA4	NM_000350.3	c.1757A>G	p.Asp586Gly	missense_variant	12/50	ENST00000370225.4
ABCA4	XM_047416704.1	c.1757A>G	p.Asp586Gly	missense_variant	12/49

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCA4	ENST00000370225.4	c.1757A>G	p.Asp586Gly	missense_variant	12/50	1	NM_000350.3	P1
ABCA4	ENST00000649773.1	c.1757A>G	p.Asp586Gly	missense_variant	12/19

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2024	ABCA4: PM3:Strong, PM2, PM5:Supporting, PP3 -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jul 29, 2023	This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 586 of the ABCA4 protein (p.Asp586Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Stargardt Disease (PMID: 29925512). ClinVar contains an entry for this variant (Variation ID: 438089). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Macular dystrophy Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

NIHR Bioresource Rare Diseases, University of Cambridge

Jan 01, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.78
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
Cadd	Pathogenic	32
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;.
Eigen	Uncertain	0.51
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.89	D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.7	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-6.0	D;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.015	D;.
Sift4G	Benign	0.095	T;.
Polyphen		0.60	P;.
Vest4		0.93
MutPred		0.43		Loss of helix (P = 0.0093);Loss of helix (P = 0.0093);
MVP		0.96
MPC		0.53
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.75
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.67		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.67		Position offset: 1
DS_DL_spliceai		0.49		Position offset: -3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553192682; hg19: chr1-94528671;