1-94001046-C-T

Variant names:

• chr1-94001046-C-T
• rs61748520
• NM_000350.3:c.6342G>A

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PS3 PP3 PP5_Very_Strong

The NM_000350.3(ABCA4):​c.6342G>A​(p.Val2114Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,614,078 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV005685550: RNA studies demonstrate a damaging effect: a "leaky" splice defect resulting in an out-of-frame transcript (PMID:23918662); SCV001164561: In vitro functional studies with keratinocytes from a patient with the variant in the heterozygous state provide some evidence that the c.6342G>A variant may impact protein function by creating a premature donor splice site, causing exon skipping of Exon 46 (PMID:23918662).; SCV004114590: Functional studies support its pathogenicity (Braun et al. 2013. PubMed ID: 23918662; Carss et al. 2016. PubMed ID: 28041643).".

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: ABCA4 NM_000350.3 synonymous
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8 O:1
• Conservation: PhyloP100: 0.552
• Publications: 4 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
• age related macular degeneration 2

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 13 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV005685550: RNA studies demonstrate a damaging effect: a "leaky" splice defect resulting in an out-of-frame transcript (PMID: 23918662); SCV001164561: In vitro functional studies with keratinocytes from a patient with the variant in the heterozygous state provide some evidence that the c.6342G>A variant may impact protein function by creating a premature donor splice site, causing exon skipping of Exon 46 (PMID: 23918662).; SCV004114590: Functional studies support its pathogenicity (Braun et al. 2013. PubMed ID: 23918662; Carss et al. 2016. PubMed ID: 28041643).
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 1-94001046-C-T is Pathogenic according to our data. Variant chr1-94001046-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 99452.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	NM_000350.3	MANE Select	c.6342G>A	p.Val2114Val	synonymous	Exon 46 of 50	NP_000341.2	P78363
	ABCA4	NM_001425324.1		c.6120G>A	p.Val2040Val	synonymous	Exon 45 of 49	NP_001412253.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ABCA4	ENST00000370225.4	TSL:1 MANE Select	c.6342G>A	p.Val2114Val	synonymous	Exon 46 of 50	ENSP00000359245.3	P78363

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 32

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: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251420 AF XY: 0.0000221

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: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000889 AC: 13 AN: 1461880 Hom.: 0 Cov.: 33 AF XY: 0.00000825 AC XY: 6 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000117 AC: 13 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74362

African (AFR) AF: 0.0000241 AC: 1 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000510 Hom.: 0

Bravo AF: 0.0000189

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (4)
2	-	-	Severe early-childhood-onset retinal dystrophy (2)
1	-	-	ABCA4-related disorder (1)
1	-	-	Retinal dystrophy (1)
1	-	-	Severe early-childhood-onset retinal dystrophy;C1858806:Cone-rod dystrophy 3;C1866422:Retinitis pigmentosa 19;C3495438:Age related macular degeneration 2 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.33
CADD	Benign	17
DANN	Benign	0.79
PhyloP100		0.55
Mutation Taster		=100/0	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.68		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.68		Position offset: 3
DS_DL_spliceai		0.60		Position offset: -44

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

Other links and lift over

dbSNP: rs61748520; hg19: chr1-94466602;