chr1-93993090-G-A

Variant names:

• chr1-93993090-G-A
• rs773349580
• NM_000350.3:c.*147C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000350.3(ABCA4):​c.*147C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000259 in 1,031,946 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00015 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00028 (0 hom.)
• Consequence: ABCA4 NM_000350.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:5
• Conservation: PhyloP100: -2.67
• Publications: 0 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_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.96).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABCA4	NM_000350.3	c.*147C>T		3_prime_UTR_variant	Exon 50 of 50	ENST00000370225.4	NP_000341.2
ABCA4	NM_001425324.1	c.*147C>T		3_prime_UTR_variant	Exon 49 of 49		NP_001412253.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCA4	ENST00000370225.4	c.*147C>T		3_prime_UTR_variant	Exon 50 of 50	1	NM_000350.3	ENSP00000359245.3

Frequencies

GnomAD3 genomes AF: 0.000151 AC: 23 AN: 152066 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000309

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.000277 AC: 244 AN: 879880 Hom.: 0 Cov.: 12 AF XY: 0.000237 AC XY: 107 AN XY: 451318

African (AFR) AF: 0.0000478 AC: 1 AN: 20904

American (AMR) AF: 0.0000649 AC: 2 AN: 30838

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 20536

East Asian (EAS) AF: 0.0000295 AC: 1 AN: 33896

South Asian (SAS) AF: 0.00 AC: 0 AN: 67366

European-Finnish (FIN) AF: 0.0000232 AC: 1 AN: 43026

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3022

European-Non Finnish (NFE) AF: 0.000366 AC: 227 AN: 619890

Other (OTH) AF: 0.000297 AC: 12 AN: 40402

GnomAD4 genome AF: 0.000151 AC: 23 AN: 152066 Hom.: 0 Cov.: 32 AF XY: 0.000135 AC XY: 10 AN XY: 74266

African (AFR) AF: 0.00 AC: 0 AN: 41400

American (AMR) AF: 0.0000655 AC: 1 AN: 15266

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5182

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10600

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

European-Non Finnish (NFE) AF: 0.000309 AC: 21 AN: 68014

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000693 Hom.: 0

Bravo AF: 0.000125

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, single submitter

Submissions by phenotype

Retinitis Pigmentosa, Recessive Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Stargardt Disease, Recessive Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

ABCA4-related disorder Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Cone-Rod Dystrophy, Recessive Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Macular degeneration Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.96
CADD	Benign	0.077
DANN	Benign	0.59
PhyloP100		-2.7
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs773349580; hg19: chr1-94458646;