rs201602424

Variant names:

• chr1-94063258-G-A
• rs201602424
• NM_000350.3:c.1614C>T
• ABCA4 p.Ala538Ala

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_000350.3(ABCA4):​c.1614C>T​(p.Ala538Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000843 in 1,614,118 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 Conflicting classifications of pathogenicity (no stars). The gene ABCA4 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.00017 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000075 (0 hom.)
• Consequence: ABCA4 NM_000350.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:4
• Conservation: PhyloP100: -0.100
• Publications: 2 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: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• severe early-childhood-onset retinal dystrophy

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, 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

Specifications for ABCA4 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_benign. The variant received -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP6: Variant 1-94063258-G-A is Benign according to our data. Variant chr1-94063258-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 236083.
• BP7: Synonymous conserved (PhyloP=-0.1 with no splicing effect.

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.1614C>T	p.Ala538Ala	synonymous	Exon 12 of 50	NP_000341.2	P78363
	ABCA4	NM_001425324.1		c.1614C>T	p.Ala538Ala	synonymous	Exon 12 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.1614C>T	p.Ala538Ala	synonymous	Exon 12 of 50	ENSP00000359245.3	P78363
	ABCA4	ENST00000649773.1		c.1614C>T	p.Ala538Ala	synonymous	Exon 12 of 19	ENSP00000496882.1	A0A3B3IRV8

Frequencies

GnomAD3 genomes AF: 0.000171 AC: 26 AN: 152108 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00482

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000479

GnomAD2 exomes AF: 0.000434 AC: 109 AN: 251398 AF XY: 0.000346

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00587

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000752 AC: 110 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.0000619 AC XY: 45 AN XY: 727246

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

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

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

East Asian (EAS) AF: 0.00257 AC: 102 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112010

Other (OTH) AF: 0.000116 AC: 7 AN: 60396

GnomAD4 genome AF: 0.000171 AC: 26 AN: 152226 Hom.: 0 Cov.: 32 AF XY: 0.000188 AC XY: 14 AN XY: 74428

African (AFR) AF: 0.00 AC: 0 AN: 41526

American (AMR) AF: 0.00 AC: 0 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00484 AC: 25 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68024

Other (OTH) AF: 0.000474 AC: 1 AN: 2108

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.000178

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	ABCA4-related disorder (2)
-	1	1	Retinal dystrophy (2)
-	-	1	Inborn genetic diseases (1)
-	-	1	not provided (1)
-	1	-	Severe early-childhood-onset retinal dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	5.1
DANN	Benign	0.57
PhyloP100		-0.10
Mutation Taster		=99/1	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs201602424;

hg19: chr1-94528814;