rs61748538

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PP2PP5_Very_Strong

The NM_000350.3(ABCA4):c.658C>T(p.Arg220Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,824 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R220R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

ABCA4
NM_000350.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7O:1

Conservation

PhyloP100: 0.376

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

ABCA4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 13 uncertain in NM_000350.3

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.

PP5

Variant 1-94098904-G-A is Pathogenic according to our data. Variant chr1-94098904-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 99471.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
ABCA4	NM_000350.3 link	c.658C>T	p.Arg220Cys	missense_variant	Exon 6 of 50	ENST00000370225.4	NP_000341.2
ABCA4	NM_001425324.1 link	c.658C>T	p.Arg220Cys	missense_variant	Exon 6 of 49		NP_001412253.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4 link	c.658C>T	p.Arg220Cys	missense_variant	Exon 6 of 50	1	NM_000350.3	ENSP00000359245.3
ABCA4	ENST00000649773.1 link	c.658C>T	p.Arg220Cys	missense_variant	Exon 6 of 19			ENSP00000496882.1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152208

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000797

AC:

AN:

251044

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.0000615

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461616

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727084

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53150

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000809

AC:

AN:

1112008

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.446

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74364

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41460

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000214

Hom.:

Bravo

AF:

0.0000151

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2Other:1

Jul 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Dec 07, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 220 of the ABCA4 protein (p.Arg220Cys). This variant is present in population databases (rs61748538, gnomAD 0.007%). This missense change has been observed in individual(s) with Stargardt disease (PMID: 29854428, 29925512, 30093795). ClinVar contains an entry for this variant (Variation ID: 99471). 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%. For these reasons, this variant has been classified as Pathogenic.

Retina International

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

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.;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.

Aug 15, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Retinal dystrophy

Pathogenic:2

Jan 01, 2017

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance:Likely 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

Severe early-childhood-onset retinal dystrophy

Pathogenic:1

May 06, 2021

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with ABCA4-related disorders, including Stargardt disease 1 (MIM#248200). (I) 0106 - This gene is associated with autosomal recessive disease. However, pseudo-dominant inheritance has been suggested (PMID: 26527198). (I) 0115 - Variants in this gene are known to have variable expressivity (PMID: 31522899). (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to cysteine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 2 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (6 heterozygotes, 0 homozygotes). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. It has been reported in homozygote and compound heterozygote individuals with Stargardt disease (PMIDs: 19074458, 23953153, 25066811, 28041643, 29854428, 30093795), and in individuals with unstated zygosity (ClinVar; PMIDs: 24154662, 11328725). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Pathogenic

0.15

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.57

D;.

Eigen

Benign

-0.25

Eigen_PC

Benign

-0.42

FATHMM_MKL

Benign

0.086

LIST_S2

Benign

0.85

T;T

M_CAP

Uncertain

0.14

MetaRNN

Uncertain

0.71

D;D

MetaSVM

Benign

-0.38

MutationAssessor

Uncertain

2.1

M;.

PhyloP100

0.38

PrimateAI

Benign

0.23

PROVEAN

Benign

-1.6

N;.

REVEL

Uncertain

0.57

Sift

Benign

0.14

T;.

Sift4G

Uncertain

0.060

T;.

Vest4

0.59

ClinPred

0.47

GERP RS

1.4

Varity_R

0.090

gMVP

0.61

Mutation Taster

=86/14

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over