rs61748538

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1PP5_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:5O:1

Conservation

PhyloP100: 0.376

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 9 uncertain in NM_000350.3

PP5

Variant 1-94098904-G-A is Pathogenic according to our data. Variant chr1-94098904-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 99471.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-94098904-G-A is described in Lovd as [Likely_pathogenic]. Variant chr1-94098904-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCA4	NM_000350.3 linkuse as main transcript	c.658C>T	p.Arg220Cys	missense_variant	6/50	ENST00000370225.4
ABCA4	XM_047416704.1 linkuse as main transcript	c.658C>T	p.Arg220Cys	missense_variant	6/49

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCA4	ENST00000370225.4 linkuse as main transcript	c.658C>T	p.Arg220Cys	missense_variant	6/50	1	NM_000350.3	P1
ABCA4	ENST00000649773.1 linkuse as main transcript	c.658C>T	p.Arg220Cys	missense_variant	6/19

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

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

251044

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135668

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 SAS 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

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

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:

0.00000809

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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

Alfa

AF:

0.0000250

Hom.:

Bravo

AF:

0.0000151

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 13, 2023	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). 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. For these reasons, this variant has been classified as Pathogenic. -
not provided, no classification provided	literature only	Retina International	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2021	- -

Severe early-childhood-onset retinal dystrophy

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 06, 2021

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 -

Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Aug 15, 2021

- -

Retinal 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

Benign

0.18

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Pathogenic

0.15

Cadd

Benign

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;.

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.23

PROVEAN

Benign

-1.6

N;.

REVEL

Uncertain

0.57

Sift

Benign

0.14

T;.

Sift4G

Uncertain

0.060

T;.

Polyphen

0.95

P;.

Vest4

0.59

MutPred

0.80

Loss of MoRF binding (P = 0.0299);Loss of MoRF binding (P = 0.0299);

MVP

0.91

MPC

0.37

ClinPred

0.47

GERP RS

1.4

Varity_R

0.090

gMVP

0.61

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over