rs61748548

Positions:

• chr1-94080559-A-C
• chr1-94080559-A-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000350.3(ABCA4):​c.1018T>G​(p.Tyr340Asp) 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 Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y340S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ABCA4 NM_000350.3 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 8.79

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 5 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 chr1-94080559-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 438086.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.976
• PP5: Variant 1-94080559-A-C is Pathogenic according to our data. Variant chr1-94080559-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 7896.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr1-94080559-A-C is described in Lovd as [Likely_pathogenic]. Variant chr1-94080559-A-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCA4	NM_000350.3	c.1018T>G	p.Tyr340Asp	missense_variant	8/50	ENST00000370225.4	NP_000341.2
ABCA4	XM_047416704.1	c.1018T>G	p.Tyr340Asp	missense_variant	8/49
LOC124904222	XR_007066231.1	n.203-3170A>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4	c.1018T>G	p.Tyr340Asp	missense_variant	8/50	1	NM_000350.3	ENSP00000359245.3
ABCA4	ENST00000649773.1	c.1018T>G	p.Tyr340Asp	missense_variant	8/19			ENSP00000496882.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Severe early-childhood-onset retinal dystrophy Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Feb 01, 2000

- -

not provided Other:1

not provided, no classification provided

literature only

Retina International

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.80
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.82	D;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.5	M;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-7.1	D;.
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0020	D;.
Sift4G	Uncertain	0.024	D;.
Polyphen		0.88	P;.
Vest4		0.95
MutPred		0.84		Loss of catalytic residue at L335 (P = 0.0828);Loss of catalytic residue at L335 (P = 0.0828);
MVP		0.98
MPC		0.60
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.85
gMVP		0.89

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

Other links and lift over

dbSNP: rs61748548; hg19: chr1-94546115;