1-93997877-T-C

Position:

• chr1-93997877-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Moderate PP5_Moderate

The NM_000350.3(ABCA4):​c.6713A>G​(p.Gln2238Arg) 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 (★). Synonymous variant affecting the same amino acid position (i.e. Q2238Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ABCA4 NM_000350.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.96

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 4 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.863
• PP5: Variant 1-93997877-T-C is Pathogenic according to our data. Variant chr1-93997877-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 236150.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-93997877-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCA4	NM_000350.3	c.6713A>G	p.Gln2238Arg	missense_variant	48/50	ENST00000370225.4	NP_000341.2
ABCA4	NM_001425324.1	c.6491A>G	p.Gln2164Arg	missense_variant	47/49		NP_001412253.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4	c.6713A>G	p.Gln2238Arg	missense_variant	48/50	1	NM_000350.3	ENSP00000359245.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Severe early-childhood-onset retinal dystrophy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

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

Jan 01, 2016

- -

Retinal dystrophy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

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

Jan 01, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T;D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.97	D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.86	D;D
MetaSVM	Uncertain	0.71	D
MutationAssessor	Pathogenic	3.4	.;M
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.4	.;D
REVEL	Pathogenic	0.84
Sift	Uncertain	0.0010	.;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	.;D
Vest4		0.96
MutPred		0.56		.;Gain of catalytic residue at D2242 (P = 0.1145);
MVP		0.97
MPC		0.48
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.49
gMVP		0.62

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: rs886044764; hg19: chr1-94463433;