rs121909203

Variant names:

• chr1-94051698-C-T
• rs76157638
• NM_000350.3:c.2588G>A

Your query was ambiguous. Multiple possible variants found:

• chr1-94051698-C-T
• chr1-94051698-C-G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate

The NM_000350.3(ABCA4):​c.2588G>A​(p.Gly863Glu) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G863A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ABCA4 NM_000350.3 missense, splice_region
• Scores: Splicing: ADA: 0.6308
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.04
• Publications: 157 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 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 chr1-94051698-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 7879.
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.868

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000350.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	NM_000350.3	MANE Select	c.2588G>A	p.Gly863Glu	missense splice_region	Exon 17 of 50	NP_000341.2
	ABCA4	NM_001425324.1		c.2366G>A	p.Gly789Glu	missense splice_region	Exon 16 of 49	NP_001412253.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	ENST00000370225.4	TSL:1 MANE Select	c.2588G>A	p.Gly863Glu	missense splice_region	Exon 17 of 50	ENSP00000359245.3
	ABCA4	ENST00000649773.1		c.2366G>A	p.Gly789Glu	missense splice_region	Exon 16 of 19	ENSP00000496882.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251244 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.56
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	34
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.41	D
MutationAssessor	Pathogenic	3.5	H
PhyloP100		7.0
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-7.4	D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.64		Gain of glycosylation at T867 (P = 0.1263)
MVP		0.93
MPC		0.52
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.90
gMVP		0.93
Mutation Taster		=23/77	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.63
dbscSNV1_RF	Benign	0.61
SpliceAI score (max)		0.50		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.50		Position offset: -3

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

Other links and lift over

dbSNP: rs76157638; hg19: chr1-94517254;